Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[Brian K. White]

On 1/8/24 12:22, bir...@soigeneris.com wrote:

The TPDD2 service manual in all of its glory...

https://archive.org/details/tpdd-2-service-manual 



Jeff Birt




Oh man awesome. A real reference for the error codes and other software 
bits...


There is an actual explaination of "mystery command 0x23" !!
https://github.com/bkw777/pdd.sh/blob/6f75515c1c5b8aa74c701c0cf61069c3cd126de2/pdd.sh#L1043

There is an "execute program" command to run arbitrary machine code!
Well we already saw that in tpdd1 right in the bootstrap directions, but 
that uses dip switch setting to put the drive into a special mode, while 
this is just a normal function like any other.


Already cleared up a few mysteries. A while back I really dug in to 
stuff like the TPDD2 sector modes to add to the work KenP and KurtM and 
others already did. I was very satisfied to be able to figure some stuff 
out that were still unknown, but I was still left with some real mysteries.


What I call "cache_load" pg 96 in the service manual,
is for moving data between the disk media and the drives ram.
(here I say "load" to mean media-to-ram
and unload to mean ram-to-media)
I had:
# 5-byte request data
# 00|02 action 0=load 2=unload
# 00unknown
# 00-4F track
# 00unknown
# 00-01 sector

Now I know it is:
# 5-byte request data
# 00-02 action 0=load 1=unload 2=unload+verify
# 00track MSB (always 00)
# 00-4F track LSB
# 00side (always 00)
# 00-01 sector

Well, in the end, it's gratifying to see it doesn't change anything,
that although we didn't know what the the two 00 bytes really were,
in the end they never would be any other value and they were being 
handled correctly.


Another example, reading data from the drives ram to the client.
(pg 89)
I had:
# 4-byte request data
# 00 area  0=data 1=meta
# -04C0  offset
# 00-FC  length

I assumed it was both incomplete and probably wrong for the "meta" mode.

I called the first byte "mode" because it seemed to be some kind of mode 
switch where it did two different things depending on that byte,

and now it was in fact called mode.
And I just assumed there might be other modes but nope, just those two.

And what I called "meta" really just means reading from the drives own 
working memory vs the disk cache. So although the guesswork label isn't 
a good fit, the usage was still right.

It did seem like something like that.
I had assumed that in mode 1 that the 2 bytes in the address or offset 
field probably had some other meaning in "meta" mode, but no, it still 
means address, just now it's from the cpus working space instead of the 
sector buffer.


The "meta" mode I just got from seeing that the backup program uses this 
mode to read 4 bytes from a certain address, but using pdd.sh to poke at 
the drive and see what it does, I noticed that you can read as many 
bytes as you want from any address you want, and get back unknown random 
seeming data.


Doesn't really answer all questions. What IS the whole memory map that 
those 4 bytes come from, and what even do those 4 bytes mean? Is there 
really a larger field that just always happens to be only 4 out of 16 
bytes used, or are those 4 bytes all there are? I can clone disks by 
copying them, but I still don't know what they mean. I couldn't craft a 
totally synthetic sector & metadata for instance like I could for TPDD1.


Anyway it will be very satisfying to update everything to fill in these 
little missing mystery bytes in pdd.sh, dl2, & PDDuino.


Thank you for getting this scanned. Nice clean job to, thanks.

--
bkw

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[birt_j]

I rendered it at 300DPI and OCRd it. When you try to uber compress the file the 
schematics start to become unreadable. 

 

Jeff

 

From: M100  On Behalf Of John R. Hogerhuis
Sent: Monday, January 8, 2024 1:24 PM
To: m...@bitchin100.com
Subject: Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now 
available.

 

Birt,

 

would it be a big deal to render this to somewhat lower fidelity? Or split into 
multiple files? I'm trying to send it to my kindle scribe through Amazon's 
service.

It's 80Mb... gmail's largest attachment size is 25mb. Supposedly I could send 
it as a zipped attachment but that only brings it down to 60mb.

There's a dedicated Send To Kindle windows app but its max is 50mb. And It 
won't accept a zipped file.

 

So one 50mb file would work. Or multiple parts < 25mb each would work

 

If it is a big deal, no problem, I will look for a way to split it up or resize 
it myself.

 

-- John.

 

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[John R. Hogerhuis]

Perfect, thanks Steve. Now I can curl up in bed with the TPDD2 manual on my
Kindle Scribe.

Hosted at

https://bitchin100.com/files/hardware/TPDD2_Service_Manual.pdf

-- John.

On Mon, Jan 8, 2024 at 11:48 AM Steve Baker  wrote:

> Greetings! Thanks for the opportunity to send this along — hopefully it’ll
> work!
>
> Cheers and thanks,
> Steve
>
>

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[John R. Hogerhuis]

If you email it to me jho...@pobox.com I can upload it to a bitchin100 file
area and I'll share the link.

-- John.

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[Steve Baker]

Hello folks — I was able to compress the PDF to about 15mb at 144 psi, medium 
quality. The compressed file looks good and the detailed bits are quite 
legible. Might there be a place where I could upload or send the file?

Cheers,
SB


--
Greetings from Steve Baker (he/him/his)
“Gravity brings me down…”




> On Jan 8, 2024, at 2:24 PM, John R. Hogerhuis  wrote:
> 
> Birt,
> 
> would it be a big deal to render this to somewhat lower fidelity? Or split 
> into multiple files? I'm trying to send it to my kindle scribe through 
> Amazon's service.
> 
> It's 80Mb... gmail's largest attachment size is 25mb. Supposedly I could send 
> it as a zipped attachment but that only brings it down to 60mb.
> 
> There's a dedicated Send To Kindle windows app but its max is 50mb. And It 
> won't accept a zipped file.
> 
> So one 50mb file would work. Or multiple parts < 25mb each would work
> 
> If it is a big deal, no problem, I will look for a way to split it up or 
> resize it myself.
> 
> -- John.
> 

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[Walt Perko]

Hi, 

 

Try MS WORD to split it into two parts.  

 

 

 

 

 

==
C U L8r,  °|°  Walt Perko  °|°"Kids ... teach them the good stuff, and 
they still learn the bad stuff on their own."

  http://www.R2Pv1.com/  RoboGuts™ Intelligent content 
for 3D printing making S.T.E.A.M. education better, easier and more affordable  

 

Experiments to learn how to use various Electronic Components, Structured 
Computer Programming, Phonemes for Speech &Song in any language, and Art.


 "The World Needs a New Economic Model"
==



Sent from the Cyber7 

 

 

From: M100 On Behalf Of John R. Hogerhuis
Sent: Monday, January 8, 2024 11:24 AM
To: m...@bitchin100.com
Subject: Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now 
available.

 

Birt,

 

would it be a big deal to render this to somewhat lower fidelity? Or split into 
multiple files? I'm trying to send it to my kindle scribe through Amazon's 
service.

It's 80Mb... gmail's largest attachment size is 25mb. Supposedly I could send 
it as a zipped attachment but that only brings it down to 60mb.

There's a dedicated Send To Kindle windows app but its max is 50mb. And It 
won't accept a zipped file.

 

So one 50mb file would work. Or multiple parts < 25mb each would work

 

If it is a big deal, no problem, I will look for a way to split it up or resize 
it myself.

 

-- John.

 

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[John R. Hogerhuis]

Birt,

would it be a big deal to render this to somewhat lower fidelity? Or split
into multiple files? I'm trying to send it to my kindle scribe through
Amazon's service.

It's 80Mb... gmail's largest attachment size is 25mb. Supposedly I could
send it as a zipped attachment but that only brings it down to 60mb.

There's a dedicated Send To Kindle windows app but its max is 50mb. And It
won't accept a zipped file.

So one 50mb file would work. Or multiple parts < 25mb each would work

If it is a big deal, no problem, I will look for a way to split it up or
resize it myself.

-- John.

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[Tim Russell]

Thanks, I figured it HAD to be a typo, otherwise it would be rather ironic
for it to have more than 5x as much RAM as the standard 100 could support.

On Mon, Jan 8, 2024, 12:05 Darren Clark  wrote:

> I think the 128K or RAM is a typo and should only be 128 bytes. Looking at
> page 97 (set the data to drive's memory) and page 89 (get the data from the
> drive's memory), there is only enough room to request 125 bytes at a time.
>
> Also from my disassembly of the TPDD1 ROM and the very similar
> architecture (same CPU and RAM and CPLD), there is only 128 bytes of
> scratch ram.
>

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[Darren Clark]

I think the 128K or RAM is a typo and should only be 128 bytes. Looking 
at page 97 (set the data to drive's memory) and page 89 (get the data 
from the drive's memory), there is only enough room to request 125 bytes 
at a time.


Also from my disassembly of the TPDD1 ROM and the very similar 
architecture (same CPU and RAM and CPLD), there is only 128 bytes of 
scratch ram.



Darren Clark



On 1/8/24 13:55, Tim Russell wrote:
Geez, up-front the manual said 128K of RAM!  I was thinking one could 
reprogram the ROM to make it a ram disk for a sec there, but the parts 
list only shows 2K of SRAM unless I missed something?


Anyway, thanks much for the efforts, all!  Great stuff.

Tim


On Mon, Jan 8, 2024, 10:23  wrote:

The TPDD2 service manual in all of its glory...

https://archive.org/details/tpdd-2-service-manual

Jeff Birt

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[John R. Hogerhuis]

In LaddieAlpha source, I have the following mystery commands:

14, // $0E
35, // $23
48, // $30
49 // $31

14 /$0E remains a mystery.
23 is Get Version Number...solved!
48 is Read/Write Data in Sector Mode... I guess that was already solved it
just didn't matter to Laddie
49 is Read/Write Data to sector or drive RAM

So very nice stuff to have.
I guess with 49 writing to Drive RAM, TPDD2 could be a coprocessor with
128K of RAM? Maybe LaddieAlpha could get a 6301 emulation?

Also the Error Code table is very nice.

-- John.

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[Tim Russell]

Geez, up-front the manual said 128K of RAM!  I was thinking one could
reprogram the ROM to make it a ram disk for a sec there, but the parts list
only shows 2K of SRAM unless I missed something?

Anyway, thanks much for the efforts, all!  Great stuff.

Tim


On Mon, Jan 8, 2024, 10:23  wrote:

> The TPDD2 service manual in all of its glory...
>
>
>
> https://archive.org/details/tpdd-2-service-manual
>
>
>
> Jeff Birt
>

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[Kurt McCullum]

Thanks Jeff,

A lot of this looks similar to the TPDD1 with the exception of the sector 
protocols. Quite a few years ago I wrote some software to copy sectors. It 
would have been nice to have had this at the time. Great to finally have it.

Kurt

On Mon, Jan 8, 2024, at 9:22 AM, bir...@soigeneris.com wrote:
> The TPDD2 service manual in all of its glory...
>  
> https://archive.org/details/tpdd-2-service-manual
>  
> Jeff Birt

Re: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[Ken St. Cyr]

Wonderful quality scans – thanks Jeff!

//Ken S

From: M100  on behalf of 
bir...@soigeneris.com 
Date: Monday, January 8, 2024 at 12:23 PM
To: m...@bitchin100.com 
Subject: [M100] Tandy Portable Disk Drive 2 service manual PDF now available.
The TPDD2 service manual in all of its glory...

https://archive.org/details/tpdd-2-service-manual

Jeff Birt

[M100] Tandy Portable Disk Drive 2 service manual PDF now available.

[birt_j]

The TPDD2 service manual in all of its glory...

 

https://archive.org/details/tpdd-2-service-manual

 

Jeff Birt