SmartBASIC - A Coleco Adam Forum

I thought of this a few days ago. Take a raspberry pi. Write a tms9928 emulator in c, python or other language. Hook up the data pins on the Adams vdp to the gpio pins of the pi as input only. Then have the emulator read what is being sent to the vdp and emulate it on the pi, displaying it on the hdmi screen. I know I am simplifying things but the vdp is simple - the Adam sends a command and then data. The pi will only process the data for display, it won’t send anything back to the Adam - let the internal vdp do that.

This is not to be confused with the F18 or others - this is a totally different take on upgrading the Adam - while the pi is there it could also be used for other things - drive emulation - serial port etc. what do you think?

Should work in theory. Writing that emulator is not for the faint-hearted however

Wmaalouli wrote: ↑

Sun Jul 21, 2019 11:33 pm

Should work in theory. Writing that emulator is not for the faint-hearted however

Actually it may be - using the source code in the ADAMem- it already emulates the vdp

Sounds like a worthy project.

I've always thought that the RPi is a perfect companion for most classic computers. If the software was there, it could be a wifi modem, SD card reader, USB printer interface, USB keyboard interface, joystick interface... and so on. 80 columns? Sure, why not. It could take the Adam into a whole new direction.

Would it be simpler just to use a SCART cable to HDMI?

G8rDuc wrote: ↑

Wed Jul 31, 2019 8:01 am

Would it be simpler just to use a SCART cable to HDMI?

The adam doesn't have Scart output - just composite and RF. I have tried the upscalers and they do not work very well.

If someone is offering to do the 9928 emulation on the Pi if hardware is provided, I can provide the hardware.

The easiest method, in terms of communication between the Z80 and the replacement 9928 is to replace its register set by an emulated set. Then use software and a small state machine to recreate what would be displayed. The Pi has a very accessible framebuffer that is highly configurable. It can upscale to 1080P transparently and simply.

If this is the appropriate place, we can discuss hardware and emulator options and do something quite quickly.

For reference, the datasheet with programmer's model is here:
http://www.bitsavers.org/components/ti/ ... _Nov82.pdf