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
