Re: [M100] z88 and tandy portable disk drive

[Brian K. White]

On 9/8/20 9:46 AM, Josh Malone wrote:
On Tue, Sep 8, 2020 at 9:31 AM Brian White > wrote:



Another option is, You can buy a pre-made tpdd cable from
arcadeshopper.com  right now.

But it has the wrong plug for z88. And the z88's serial port is
non-standard, so there are no off-the-shelf adapters or  combination
of adapters to get you from the z88 to the normal tpdd cable.

You're making a custom adapter or cable of some sort one way or
another no matter what.

Maybe it's worth making a short adapter cable that doesn't do
anything but just convert the z88 serial port to a standard plug and
standard pinout. Either a male 9-pin like a pc, or a female 25-pin
like a "Model T".


This is what I plan to do, once I get 'round to it. Once you get a 
standard RS232-C port on the Z88, you have many options, including the 
TPDD via the usual cable.


-Josh


I knocked up a couple pcb adapters, one that provides a 9-pin male DTE 
like a PC, and one that provides a 25 pin female DTE, like a Model 100.

https://github.com/bkw777/Z88_RS232

But I think a short cable would be more advisable because of how the pcb 
has to be offset, making it likely the cable falls out of the connector 
easily.


At least the schematic helps make it easy to wire up, since you can just 
go by the pin numbers.


--
bkw

Re: [M100] z88 and tandy portable disk drive

[Josh Malone]

On Tue, Sep 8, 2020 at 9:31 AM Brian White  wrote:

>
> Another option is, You can buy a pre-made tpdd cable from
> arcadeshopper.com right now.
>
> But it has the wrong plug for z88. And the z88's serial port is
> non-standard, so there are no off-the-shelf adapters or  combination of
> adapters to get you from the z88 to the normal tpdd cable.
>
> You're making a custom adapter or cable of some sort one way or another no
> matter what.
>
> Maybe it's worth making a short adapter cable that doesn't do anything but
> just convert the z88 serial port to a standard plug and standard pinout.
> Either a male 9-pin like a pc, or a female 25-pin like a "Model T".
>

This is what I plan to do, once I get 'round to it. Once you get a standard
RS232-C port on the Z88, you have many options, including the TPDD via the
usual cable.

-Josh

Re: [M100] z88 and tandy portable disk drive

[Brian White]

Just to be clear, I'm not suggesting you actually get all the stuff to
build a Feather MounT for Z88 and get an Adafruit Feather board and run
PDDuino on it, unless you actually wanted to play with something new and
shakey just for the fun of it.

It's neat, and it mostly works, but the code running on it is not
bulletproof yet. I can't promise that it never corrupts data. I can't even
promise it works at all with the tpdd client software for the Z88. It has
several known bugs described on the github readme, and it doesn't even work
with TEENY, even though it does work with TS-DOS (two different tpdd
clients). If it doesn't work with one known good tpdd client, then it might
not work with a new completely unknown one (z88 diskmgr).

I AM suggesting to actually build the Z88 version of the cable using the
recipe from http://tandy.wiki/TPDD#Cable

Another option is, You can buy a pre-made tpdd cable from arcadeshopper.com
right now.

But it has the wrong plug for z88. And the z88's serial port is
non-standard, so there are no off-the-shelf adapters or  combination of
adapters to get you from the z88 to the normal tpdd cable.

You're making a custom adapter or cable of some sort one way or another no
matter what.

Maybe it's worth making a short adapter cable that doesn't do anything but
just convert the z88 serial port to a standard plug and standard pinout.
Either a male 9-pin like a pc, or a female 25-pin like a "Model T".

Then, you could use any/all otherwise normal cables and accessories and
standard off the shelf adapters with that as needed, like gender-changers,
9to25, null-modem etc.

Then you could just buy a pre-made normal tpdd cable meant for a Model 100
or NEC etc.

Then tomorrow when you want to do something else like connect a WiModem
instead of a TPDD, you won't need another custom cable, just your
z88-to-Normal adapter and an ordinary/standard gender-changer or 9-to-25
adapter. Then the same thing for null-modem to a pc, for a printer, etc.

-- 
bkw

On Mon, Sep 7, 2020, 1:25 PM Brian White  wrote:

> Ooh I can add a Z88 version of https://github.com/bkw777/MounT to use
> with https://github.com/bkw777/PDDuino too.
>
> Though, the 1ma power output from the DTR pin on the serial port isn't
> enough to power a Feather or Teensy.
>
> The Mode T's except for KC-85 all have a BCR port which provides enough
> power (using https://github.com/bkw777/BCR_Breakout), but the Z88 doesn't
> have that.
> The expansion connectors don't look good to use for this because you want
> them to remain usable for carts.
>
> So, There are versions of MounT for Teensy and Feather, and out of those
> two, Feather boards have on-board lipo battery managers and a jst
> connector. So for a Z88 it makes the most sense to use a Feather version
> and include the battery (already included in the BOM anyways for
> reference). You leave the lipo cell connected to the board all the time,
> and charge it by just connecting a usb cable to the Feather.
>
>
>
> On Mon, Sep 7, 2020 at 1:14 PM Brian White  wrote:
>
>> Good grief the pin numbers for the DE9F are wrong on that drawing too. I
>> can't make sense of that drawing at all, and so I'm ignoring it.
>>
>> I'm going to go by the actual user manual. That too has one slight
>> confusion but not really.
>> At first glance it looks like it's saying there is a 9pin male connector
>> on the z88, but it's really saying to use a 9pin male connector to make a
>> cable.
>> https://archive.org/details/aa153-Z88_User_Guide/page/n235/mode/2up
>>
>> It's neat that they included an explicit provision for powering rs-232 to
>> cmos level shifters (max232, max3232).
>>
>> This also shows a female connector on the z88, so between the pics and
>> the manual, I'm going ahead assuming it's a female connector on the Z88.
>> https://oldcrap.org/2019/10/28/cambridge-z88/
>>
>> I've updated the wiki and github project to include Z88 versions of the
>> schematic, PCB, and BOM.
>> http://tandy.wiki/TPDD#Cable
>>
>> Untested of course. I don't have a Z88 and only just updated the drawings
>> now. But it's all tested with Model 100 and other "Model T"s, so as long as
>> the original Z88 manual isn't lying, then it's good to go.
>>
>> For future reference, note that pin numbers for both male and female
>> plugs are the same, in the sense that, pin#1 of a male plug plugs in to
>> pin#1 of a female plug.
>> That means that, regardless if you're looking at the front on the
>> connector where the pins are, or the back where the solder legs are,
>> and regardless if you are talking about the port on a device or the end
>> of a cable that plugs into that device,
>> pin#1 always means the same pin#1.
>> IE, pin#1 on the device does not connect to say pin#6 on the cable. It
>> connects to pin#1 on the cable.
>>
>> So, the way to avoid getting confused is, always use the correct pin
>> numbers according to standards, and expect everyone else (official) to have
>> done so also, and then, you don't care if you're 

Re: [M100] z88 and tandy portable disk drive

[Brian White]

Ooh I can add a Z88 version of https://github.com/bkw777/MounT to use with
https://github.com/bkw777/PDDuino too.

Though, the 1ma power output from the DTR pin on the serial port isn't
enough to power a Feather or Teensy.

The Mode T's except for KC-85 all have a BCR port which provides enough
power (using https://github.com/bkw777/BCR_Breakout), but the Z88 doesn't
have that.
The expansion connectors don't look good to use for this because you want
them to remain usable for carts.

So, There are versions of MounT for Teensy and Feather, and out of those
two, Feather boards have on-board lipo battery managers and a jst
connector. So for a Z88 it makes the most sense to use a Feather version
and include the battery (already included in the BOM anyways for
reference). You leave the lipo cell connected to the board all the time,
and charge it by just connecting a usb cable to the Feather.



On Mon, Sep 7, 2020 at 1:14 PM Brian White  wrote:

> Good grief the pin numbers for the DE9F are wrong on that drawing too. I
> can't make sense of that drawing at all, and so I'm ignoring it.
>
> I'm going to go by the actual user manual. That too has one slight
> confusion but not really.
> At first glance it looks like it's saying there is a 9pin male connector
> on the z88, but it's really saying to use a 9pin male connector to make a
> cable.
> https://archive.org/details/aa153-Z88_User_Guide/page/n235/mode/2up
>
> It's neat that they included an explicit provision for powering rs-232 to
> cmos level shifters (max232, max3232).
>
> This also shows a female connector on the z88, so between the pics and the
> manual, I'm going ahead assuming it's a female connector on the Z88.
> https://oldcrap.org/2019/10/28/cambridge-z88/
>
> I've updated the wiki and github project to include Z88 versions of the
> schematic, PCB, and BOM.
> http://tandy.wiki/TPDD#Cable
>
> Untested of course. I don't have a Z88 and only just updated the drawings
> now. But it's all tested with Model 100 and other "Model T"s, so as long as
> the original Z88 manual isn't lying, then it's good to go.
>
> For future reference, note that pin numbers for both male and female plugs
> are the same, in the sense that, pin#1 of a male plug plugs in to pin#1 of
> a female plug.
> That means that, regardless if you're looking at the front on the
> connector where the pins are, or the back where the solder legs are,
> and regardless if you are talking about the port on a device or the end of
> a cable that plugs into that device,
> pin#1 always means the same pin#1.
> IE, pin#1 on the device does not connect to say pin#6 on the cable. It
> connects to pin#1 on the cable.
>
> So, the way to avoid getting confused is, always use the correct pin
> numbers according to standards, and expect everyone else (official) to have
> done so also, and then, you don't care if you're dealing with a male or
> female plug, you just know that you need for example, the ground goes on
> pin #7. Then, on the connector itself, the pins are individually numbered
> explicitly so you don't have to guess which one is pin#7. You can also
> always google up references for standard connectors themselves, regardless
> what kind of device is using the connector or what kind of signals are on
> it.
>
> The same goes for the rectangular pin headers and IDC connectors. There is
> a specific location for pin#1, and a specific numbering pattern to proceed
> from pin#1. They aren't individually labeled on IDC connectors, or labelled
> at all on plain pin headers, but either the connector or the pcb silkscreen
> will always indicate where pin#1 is, and you follow the standard to number
> the rest. The TPDD drive adheres to the standard for the 2x4 pin header on
> the back.
>
> So, the z88 manual lists signals and pin numbers for the de9 plug on it's
> end, and the tpdd manual lists pin numbers and signals for the 2x4 pin
> header on it's end, and it's possible to derive a correct cabling between
> the two without having to guess about anything like what the author means
> by "front", and without the confusion introduced by things like that
> drawing which uses pin numbers, but all incorrect pin numbers.
> --
> bkw
>

Re: [M100] z88 and tandy portable disk drive

[Brian White]

Good grief the pin numbers for the DE9F are wrong on that drawing too. I
can't make sense of that drawing at all, and so I'm ignoring it.

I'm going to go by the actual user manual. That too has one slight
confusion but not really.
At first glance it looks like it's saying there is a 9pin male connector on
the z88, but it's really saying to use a 9pin male connector to make a
cable.
https://archive.org/details/aa153-Z88_User_Guide/page/n235/mode/2up

It's neat that they included an explicit provision for powering rs-232 to
cmos level shifters (max232, max3232).

This also shows a female connector on the z88, so between the pics and the
manual, I'm going ahead assuming it's a female connector on the Z88.
https://oldcrap.org/2019/10/28/cambridge-z88/

I've updated the wiki and github project to include Z88 versions of the
schematic, PCB, and BOM.
http://tandy.wiki/TPDD#Cable

Untested of course. I don't have a Z88 and only just updated the drawings
now. But it's all tested with Model 100 and other "Model T"s, so as long as
the original Z88 manual isn't lying, then it's good to go.

For future reference, note that pin numbers for both male and female plugs
are the same, in the sense that, pin#1 of a male plug plugs in to pin#1 of
a female plug.
That means that, regardless if you're looking at the front on the connector
where the pins are, or the back where the solder legs are,
and regardless if you are talking about the port on a device or the end of
a cable that plugs into that device,
pin#1 always means the same pin#1.
IE, pin#1 on the device does not connect to say pin#6 on the cable. It
connects to pin#1 on the cable.

So, the way to avoid getting confused is, always use the correct pin
numbers according to standards, and expect everyone else (official) to have
done so also, and then, you don't care if you're dealing with a male or
female plug, you just know that you need for example, the ground goes on
pin #7. Then, on the connector itself, the pins are individually numbered
explicitly so you don't have to guess which one is pin#7. You can also
always google up references for standard connectors themselves, regardless
what kind of device is using the connector or what kind of signals are on
it.

The same goes for the rectangular pin headers and IDC connectors. There is
a specific location for pin#1, and a specific numbering pattern to proceed
from pin#1. They aren't individually labeled on IDC connectors, or labelled
at all on plain pin headers, but either the connector or the pcb silkscreen
will always indicate where pin#1 is, and you follow the standard to number
the rest. The TPDD drive adheres to the standard for the 2x4 pin header on
the back.

So, the z88 manual lists signals and pin numbers for the de9 plug on it's
end, and the tpdd manual lists pin numbers and signals for the 2x4 pin
header on it's end, and it's possible to derive a correct cabling between
the two without having to guess about anything like what the author means
by "front", and without the confusion introduced by things like that
drawing which uses pin numbers, but all incorrect pin numbers.
-- 
bkw

Re: [M100] z88 and tandy portable disk drive

[Brian White]

Also the pin numbering for the tpdd socket is wrong on that drawing. There
is a standard for how pins are numbered on plain pin headers and IDC
connectors, so, the visual description of which wires go to which pins may
be correct, but only consider those pin numbers within that drawing itself.
The drawing on the wiki page has the actual pin numbers which is not only
according to the standard, but also matches the schematic in the service
manual for the drive.



On Mon, Sep 7, 2020 at 8:31 AM Brian White  wrote:

> That cable diagram doesn't show anything to translate between TTL for the
> drive and RS232 for the computer. Maybe it still works by luck but I
> wouldn't use it.
>
> The drive uses TTL voltages that range from 0 to +5v, while RS232 uses
> voltages that range from -N to +N, where N is anything from 5 to 15, with a
> no-mans-land in the middle from -3v to +3v (which includes 0v)
>
> So you really want a circuit that converts between the two. The normal
> TPDD cable got away with 3 internally biased transistors to do this without
> a real max232 chip. It doesn't do the full proper job like a max232 chip,
> but it does enough.
>
> You can build a proper cable using this little pcb and a factory serial
> cable with one end cut off,
>
> http://tandy.wiki/TPDD#Cable
>
> ...with all the same parts but a few different directions.
>
> According to
> https://worldofspectrum.org/z88forever/tech/hardware.htm
> The connector on the z88 is male db9, so, the cable in the BOM already
> works for this too, just you'd need to cut off the db25 end instead of
> cutting off the de9 end. And you'd have to translate the pin numbers
> written on the pcb to the de9 pinpin and the z88's non-standard pinout. I
> can add explicit directions for that in a few minutes to remove any
> guesswork about that.
>
> However, I'm confused. This shows a female de9 port?
> http://www.larwe.com/museum/z88.html
>
> Do you in fact have a male or female port on the unit in your hands?
> If they actually have female ports, then I'll just make a separate BOM
> with a different cable and separate version of the pcb with different
> writing on it.
> (Even if you don't want to build a cable this way, I still just want the
> project to include this for completeness, since there is software to use
> the drive on that machine.)
>
> --
> bkw
>
> On Sun, Sep 6, 2020, 2:39 PM dano none  wrote:
>
>>
>> Has anyone tried hooking up a Tandy Portable Disk Drive to a Cambridge
>> Z88?
>>
>> The instructions are here:
>>
>> http://www.rakewell.com/xob/xob.shtml
>>
>> I think in the instructions to build a cable is says front of connector,
>> I think that means - looking in to the cable from the front.
>>
>> Anyway, has anyone done this? Looks like the little Tandy Portable lived
>> a very exciting life, hooking up with Tandys, Z88's and even knitting
>> machines!
>>
>> 
>> Rakewell's Z88 Archive Page 
>> 1. Introduction. Disc-88 is a portable, battery-powered disc drive for
>> the Z88 computer. It uses readily available 3.5 inch floppy discs as the
>> storage medium.
>> www.rakewell.com
>>
>>

Re: [M100] z88 and tandy portable disk drive

[Brian White]

That cable diagram doesn't show anything to translate between TTL for the
drive and RS232 for the computer. Maybe it still works by luck but I
wouldn't use it.

The drive uses TTL voltages that range from 0 to +5v, while RS232 uses
voltages that range from -N to +N, where N is anything from 5 to 15, with a
no-mans-land in the middle from -3v to +3v (which includes 0v)

So you really want a circuit that converts between the two. The normal TPDD
cable got away with 3 internally biased transistors to do this without a
real max232 chip. It doesn't do the full proper job like a max232 chip, but
it does enough.

You can build a proper cable using this little pcb and a factory serial
cable with one end cut off,

http://tandy.wiki/TPDD#Cable

...with all the same parts but a few different directions.

According to
https://worldofspectrum.org/z88forever/tech/hardware.htm
The connector on the z88 is male db9, so, the cable in the BOM already
works for this too, just you'd need to cut off the db25 end instead of
cutting off the de9 end. And you'd have to translate the pin numbers
written on the pcb to the de9 pinpin and the z88's non-standard pinout. I
can add explicit directions for that in a few minutes to remove any
guesswork about that.

However, I'm confused. This shows a female de9 port?
http://www.larwe.com/museum/z88.html

Do you in fact have a male or female port on the unit in your hands?
If they actually have female ports, then I'll just make a separate BOM with
a different cable and separate version of the pcb with different writing on
it.
(Even if you don't want to build a cable this way, I still just want the
project to include this for completeness, since there is software to use
the drive on that machine.)

-- 
bkw

On Sun, Sep 6, 2020, 2:39 PM dano none  wrote:

>
> Has anyone tried hooking up a Tandy Portable Disk Drive to a Cambridge Z88?
>
> The instructions are here:
>
> http://www.rakewell.com/xob/xob.shtml
>
> I think in the instructions to build a cable is says front of connector, I
> think that means - looking in to the cable from the front.
>
> Anyway, has anyone done this? Looks like the little Tandy Portable lived a
> very exciting life, hooking up with Tandys, Z88's and even knitting
> machines!
>
> 
> Rakewell's Z88 Archive Page 
> 1. Introduction. Disc-88 is a portable, battery-powered disc drive for the
> Z88 computer. It uses readily available 3.5 inch floppy discs as the
> storage medium.
> www.rakewell.com
>
>

Re: [M100] z88 and tandy portable disk drive

[Lee Kelley]

And Brother used a variation for embroidery machines.


Virus-free.
www.avg.com

<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

On Sun, Sep 6, 2020 at 2:33 PM Jeffrey Birt  wrote:

> Very interesting it was used on the Z88 as well. I seem to recall that the
> drive itself was a third part unit that several manufacturers used to add
> disk drive capability to their products. I don’t recall where I heard that
> off the top of my head though.
>
>
>
> Jeff Birt
>
>
>
> *From:* M100  *On Behalf Of *dano none
> *Sent:* Sunday, September 6, 2020 1:39 PM
> *To:* m100@lists.bitchin100.com
> *Subject:* [M100] z88 and tandy portable disk drive
>
>
>
>
>
> Has anyone tried hooking up a Tandy Portable Disk Drive to a Cambridge Z88?
>
>
>
> The instructions are here:
>
>
>
> http://www.rakewell.com/xob/xob.shtml
>
>
>
> I think in the instructions to build a cable is says front of connector, I
> think that means - looking in to the cable from the front.
>
>
>
> Anyway, has anyone done this? Looks like the little Tandy Portable lived a
> very exciting life, hooking up with Tandys, Z88's and even knitting
> machines!
>
>
>
> 
>
> Rakewell's Z88 Archive Page 
>
> 1. Introduction. Disc-88 is a portable, battery-powered disc drive for the
> Z88 computer. It uses readily available 3.5 inch floppy discs as the
> storage medium.
>
> www.rakewell.com
>
>
>


-- 
*"I will never in my lifetime make a film that cannot be seen by the whole
family"*  Arther P. Jacobs


Virus-free.
www.avg.com

<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

Re: [M100] z88 and tandy portable disk drive

[Josh Malone]

On Sun, Sep 6, 2020 at 3:33 PM Jeffrey Birt  wrote:

> Very interesting it was used on the Z88 as well. I seem to recall that the
> drive itself was a third part unit that several manufacturers used to add
> disk drive capability to their products. I don’t recall where I heard that
> off the top of my head though.
>
>
>
> Jeff Birt
>

It was designed and built by Brother - originally for their knitting /
sewing machines I believe. The fact that Tandy adopted it actually seems a
bit weird to me, but I guess they needed something and the serial interface
was easy enough to adapt. The usage on the Z88 certainly is not a
manufacturer-specified odd-on -- just something someone in the community
came up with.

Re: [M100] z88 and tandy portable disk drive

[Jeffrey Birt]

Very interesting it was used on the Z88 as well. I seem to recall that the
drive itself was a third part unit that several manufacturers used to add
disk drive capability to their products. I don't recall where I heard that
off the top of my head though.

 

Jeff Birt

 

From: M100  On Behalf Of dano none
Sent: Sunday, September 6, 2020 1:39 PM
To: m100@lists.bitchin100.com
Subject: [M100] z88 and tandy portable disk drive

 

 

Has anyone tried hooking up a Tandy Portable Disk Drive to a Cambridge Z88?

 

The instructions are here:

 

http://www.rakewell.com/xob/xob.shtml

 

I think in the instructions to build a cable is says front of connector, I
think that means - looking in to the cable from the front.

 

Anyway, has anyone done this? Looks like the little Tandy Portable lived a
very exciting life, hooking up with Tandys, Z88's and even knitting
machines!

 


  

  Rakewell's Z88 Archive Page

1. Introduction. Disc-88 is a portable, battery-powered disc drive for the
Z88 computer. It uses readily available 3.5 inch floppy discs as the storage
medium.

www.rakewell.com  

 

Re: [M100] z88 and tandy portable disk drive

[Josh Malone]

Sounds like a cool experiment! I recently acquired a Z88, so maybe I'll
give this a try, once I get a chance to dig into that machine a bit.

On Sun, Sep 6, 2020 at 2:39 PM dano none  wrote:

>
> Has anyone tried hooking up a Tandy Portable Disk Drive to a Cambridge Z88?
>
> The instructions are here:
>
> http://www.rakewell.com/xob/xob.shtml
>
> I think in the instructions to build a cable is says front of connector, I
> think that means - looking in to the cable from the front.
>
> Anyway, has anyone done this? Looks like the little Tandy Portable lived a
> very exciting life, hooking up with Tandys, Z88's and even knitting
> machines!
>
> 
> Rakewell's Z88 Archive Page 
> 1. Introduction. Disc-88 is a portable, battery-powered disc drive for the
> Z88 computer. It uses readily available 3.5 inch floppy discs as the
> storage medium.
> www.rakewell.com
>
>