Hi Britt,
Thanks!
The other idea besides putting this into an FPGA would be to make a real
live ASIC!!! There is an old 130nm process that Skywater and Google
have made open-source and Google has funded several multi-project-wafer
(MPW) shuttle runs in conjunction with a company called Efabless. I
tried getting a design on the first shuttle, but ended up spending a
couple of weeks in the hospital and recovery during the time leading up
to the submission deadline. Would be really cool to get a Model 401
ASIC on one of those free Google Shuttles!! :)
Ken
On 5/22/21 2:26 PM, Britt Dodd wrote:
I really wish I could figure out FPGAs! I’d love to run this and make some
hybrid M100/internet thing. Have an app that would be like the TRS-80 Prodigy
or something. PCB layouts and FPGAs are way out of my wheelhouse at the moment.
Awesome work!
Sent from my iPhone
On May 22, 2021, at 4:22 PM, Ken Pettit <petti...@gmail.com> wrote:
Hey Rob,
Actually, the time did finally advance. I forgot that this is a simulation, so
it takes quite a bit of real-time for even one second to pass in the simulated
design. It is up to 5 seconds now in my simulation after about 5-6 minutes of
real time.
Ken
On 5/22/21 12:44 PM, Ken Pettit wrote:
Hey Rob,
I have an RTL design I worked on YEARS ago where I was trying to get the Model
100 in an FPGA along with some extensions. It was back when there was a lot of
talk on the list about a Model 401. For those who weren't around then or don't
recall, the Model 401 was something that was discussed around April Fools day
(thus the number 401) about an updated Model 100.
I actually had this running somewhat on an Actel Igloo FPGA at that time, though not fully. I
believe I had extended the 8085 instruction set to add relative jump and branch opcodes using the
"MOV A,A", "MOV B,B" etc. opcodes which are basically useless and not used in
the M100 ROM. I was also planning at that time to have a 2-processor system where the LCD and
Keyboard would be shared by both the extended 8085 and an ARM core. The keyboard controller I
wrote detects a hotkey escape sequence to connect the LCD and keyboard to either the ARM interface
or the 8085 interface.
I just re-ran my RTL simulation and I see that it is at least running and generating an
output on the RTL testbench LCD monitor that I wrote. This LCD monitor in the testbench
monitors all LCD writes and outputs "pixels" as X'x to a Linux /dev/pty device.
Then with minicom connected using Linux socat, I can see what the emulation is sending to
the LCD. I have attached a snapshot of the output of the simulation (the dots are
actually very small X's, just zoomed out so it's like a 3-point font on minicom or
something). You can see the minicom status line at the bottom in a very small font. I
can see the time isn't advancing, so maybe something not quite right with the clock chip
RTL (uPD1990.v).
If you would like to use this RTL as a starting point, I'm happy to post it to
github and give you a link. The files in this design are:
-rw-rw-r-- 1 kpettit users 4108 Apr 16 2012 armspi.v
-rw-rw-r-- 1 kpettit users 97936 Apr 12 2012 cpu8085.v
-rw-rw-r-- 1 kpettit users 2468 May 8 2016 fifo1kx13sram.v
-rw-r--r-- 1 kpettit users 1531 May 9 2016 hvsync_generator.v
-rw-rw-r-- 1 kpettit users 19422 Mar 31 2012 im6402.v
-rw-rw-r-- 1 kpettit users 8344 May 6 2016 keymap.v
-rw-rw-r-- 1 kpettit users 12032 May 5 2016 keyscan.v
-rw-rw-r-- 1 kpettit users 40316 May 7 2016 lcd.v
-rw-rw-r-- 1 kpettit users 687 May 9 2016 m100rom.v
-rw-rw-r-- 1 kpettit users 6383 Apr 13 2012 mapper.v
-rw-rw-r-- 1 kpettit users 16475 May 7 2016 model401.v
-rw-r--r-- 1 kpettit users 7842 May 5 2016 nr5_tx8n.vhd
-rw-rw-r-- 1 kpettit users 6161 May 4 2016 nr5_uart.v
-rw-rw-r-- 1 kpettit users 5947 Apr 7 2012 pio8155.v
-rw-rw-r-- 1 kpettit users 1825 Mar 23 2012 ramCore512.v
-rw-rw-r-- 1 kpettit users 1836 Apr 11 2012 ramCore512x9.v
-rw-rw-r-- 1 kpettit users 9971 Apr 15 2012 socTop.v
-rw-rw-r-- 1 kpettit users 1036 May 9 2016 sram32k.v
-rw-rw-r-- 1 kpettit users 1114 May 7 2016 sram512.v
-rw-rw-r-- 1 kpettit users 1116 May 8 2016 sram512x9.v
-rw-r--r-- 1 kpettit users 9053 May 5 2016 uart_rx8n.vhd
-rw-rw-r-- 1 kpettit users 10794 Apr 7 2012 uPD1990.v
Ken
On 5/22/21 11:22 AM, Rob Messer wrote:
I have followed this email list for a years and I have never asked a
question...but here goes! I am sitting here with my model 100 and I had an idea
to 3D print a replica case and get my hands on an LCD and mechanical keyboard
and try to faithfully reproduce the Model 100 with simple additions. I have
enlisted a few friends (we are all engineers)... I was wondering of anyone
knows of an FPGA implementation of the Model 100 hardware? I want to make a
fairly faithful reproduction short of using an 80C85.
Thanks!
--
Robert Messer
BARA Sweden
