The speed mod made it to Hackaday.
https://hackaday.com/2024/02/18/doubling-the-cpu-speed-of-the-trs-80-model-100-with-a-mod-board/
> 0x13
branch to Command_FMT_Invalid
[F107] [24 2E ] [$. ] BCC Command_FMT_Invalid
The "I haven't looked..." part is true, I found it at F014 and F105. So
the firmware does protect against invalid commands.
Darren Clark
On 1/28/24 12:40, Darren Clark wr
Nice find! I wasn't looking at port 4 data since I assumed it was all
address outputs, but P43, P44, P45 are configured as inputs on the TPDD2
(not on the TPPD1).
;Port4.B0 I/O Pin37 P40 A8
;Port4.B1 I/O Pin36 P41 A9
;Port4.B2 I/O Pin35 P42 A10
and # of tracks.
Another question.. it looks like was there a second unpopulated serial
port on the drive? Anything in the code on that?
P7 is unpopulated and not in the schematic, but it is there.
Steve
On Sunday, January 28, 2024, Darren Clark wrote:
Spent some time digging
ty out of so few bytes.
--
bkw
On Sun, Jan 28, 2024, 12:19 AM Darren Clark wrote:
Spent some time digging through the source of the TPDD2 firmware,
adding
comments, labels, and variable names.
It's documented (as far as I got so far) here:
https://github.com/BiggRanger/Tand
of available space, there is only 15 bytes of unused
space, and the author put his name into it (with one byte filled with a
0xFF):
[FFDF] [***] [ ] DB '(C) M.FUTAMURA',0xFF ;Author
Darren Clark
more
complicated. It'll take a while to decipher and figure out the little
tricks that were used to save space, and also decode the functionality.
As i figure out more I'll update my GitHub and this list.
Darren Clark
On 1/24/24 19:36, Brian K. White wrote:
I'm currently parsing the retu
in there!
Darren Clark
On 1/23/24 21:27, Stephen Adolph wrote:
128 more bytes ;)
On Tue, Jan 23, 2024 at 3:28 PM Stephen Adolph
wrote:
It was a first pass attempt. I captured it as 128 blocks of 32
bytes. Was it
On Tuesday, January 23, 2024, Darren Clark
wrote:
Hello
.
Darren Clark
Here is a memory map of the TPDD1 from my reverse engineering
earlier:
;--
;Memory Map of PDD (using mode 6):
;--
;
.
Would you mind sharing the program you used to dump the firmware so I
can have a quick look through?
Darren Clark
On 1/22/24 23:21, Stephen Adolph wrote:
these look like 6301 opcodes. Maybe this worked.
take a look please when you can. thanks. Steve
On Tue, Jan 9, 2024 at 6:55 PM
my decomplier
and check the address alignments, that should prove whether the start
byte is correct or not too.
Either way, we're 95% there. Thanks for working on this!
Darren Clark
On 1/22/24 23:21, Stephen Adolph wrote:
these look like 6301 opcodes. Maybe this worked.
take a look please
state hex inverter
Darren Clark
On 1/10/24 20:05, David Plass wrote:
Hi all,
I just bought an NEC 8201 and it has a strange mod inside: there's a
daughterboard on top of the motherboard with 5 or 6 alligator clips
attached to various spots on the board including 3 or 4 on the RS-232
connector
Block - 5A5A 32 04 01 F000 40 (checksum) and see what block of
64 bytes comes out.
Darren Clark
Here is a memory map of the TPDD1 from my reverse engineering earlier:
;--
;Memory Map of PDD (using mode 6
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
nteresting to think about.
I see you have the disassembly in place.
On Fri, Mar 19, 2021 at 8:36 PM Darren Clark <mailto:biggran...@gmail.com>> wrote:
There are 2 memory modes on that processor, Mode0 which uses the
internal RAM and ROM (which is how the PDD is being used), a
; actually I would probably refuse to do this to a good
working TPPD-2.
If you're still interested in contributing to the better understating of
the inner working of the TPPD-2, drop me an e-mail and we can discuss it
further.
Darren Clark
On 3/20/21 6:40 AM, Charles Hudson wrote:
Darren
the clock,
power, mode, and reset pins, and connect it to a suitable external
memory. That is why I'm looking for a not-working PDD2 with a working
processor.
Darren Clark
On 3/19/21 7:18 PM, Stephen Adolph wrote:
I wonder if there is a way to boot that processor off of external
memory
And the whole project: https://github.com/BiggRanger/Tandy_PDD
Maybe if someone has a bad TPDD2 or 2 I can try to get the firmware off
of that too.
Darren Clark
On 3/18/21 9:59 PM, Brian K. White wrote:
On 3/18/21 8:31 PM, Joshua O'Keefe wrote:
On Mar 18, 2021, at 5:13 PM, Stephen Adolph
.
https://github.com/BiggRanger/Tandy_PDD
Darren Clark
On 3/18/21 9:59 PM, Brian K. White wrote:
On 3/18/21 8:31 PM, Joshua O'Keefe wrote:
On Mar 18, 2021, at 5:13 PM, Stephen Adolph <mailto:twospru...@gmail.com>> wrote:
so I did it brute-force.
https://bitchin100.com/wiki/index.
Ken,
Wishing you all the best, take care, rest, and let the doctors do
their magic!
On 11/9/20 9:37 PM, Kenneth Pettit wrote:
Hey gang,
Well I’m back in the hospital again with angina and shortness of breath.
Hopefully it will be just. A couple of days for a stent or two and then
Ken,
Wishing you all the best, take care, rest, and let the doctors do
their magic!
On 11/9/20 9:37 PM, Kenneth Pettit wrote:
Hey gang,
Well I’m back in the hospital again with angina and shortness of breath.
Hopefully it will be just. A couple of days for a stent or two and then
Thinking about bumping my laptop from 16GB to 32GB, 2x 8GB DDR3 RAM is
$49.99. No, too expensive
Thinking back to this weekend... 2x 24KB modules for my Tandy 200 on
eBay for $46.64, PURCHASE! I'll get them Friday (I hope).
It's interesting where the priorities are.
Darren Clark
Thank you very much! It's working now, I can ask for a status and
receive the reply!
Darren Clark
On 8/5/20 10:36 AM, Ron Lauzon wrote:
You can have the COM port open for both input and output at the same time.
I did a TPDD-ish experiment a while ago and wrote some BASIC programs
to work
ng. I think it may be
clearing the input buffer when opening the port.
I want to create a subroutine the sends a command to check the status of
the plotter, receive the string back and parse it to see if the plotter
is busy and keep looping until it's not busy, or there is an error. I
just can't figuer out sending and receiving over serial with the 200.
Darren Clark
I ordered all my belts from here: https://www.turntableneedles.com/
Darren
On 4/25/20 3:37 AM, Jonathan Yuen wrote:
Hello,
Just out of curiosity, where does one order belts for an old cassette tape
recorder? I have a Superscope CD-320 and while it works (mostly) OK, the belt
for the
I have a CCR-81 and a CCR-82, both are running great with only replacing
the belts. Audio is just fine and my Model 200 can load programs off of
30+ year old cassette tapes.
Darren
On 4/24/20 9:17 PM, Doug Jackson wrote:
I'm not confident that the capacitors will need replacing.
There
I remember a discussion a year or 2 back about 3D printing them.
Someone posted files on ThingiVerse here ->
https://www.thingiverse.com/thing:3821586
On 3/7/20 4:42 PM, Dave Everett wrote:
On 8/03/2020 8:27 am, Brian K. White wrote:
On 3/7/20 11:22 AM, Stephen Adolph wrote:
hi, has
"hi club 100!"
Love it, great article!
Thanks for sharing.
On 12/1/19 11:57 AM, Mitch Parker wrote:
Good afternoon!
I write monthly for CSO Online, and was able to write a large chunk of
my July blog on my 102.
It's about data conversion and the challenges we face with legacy data
and
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