using BASCOM-8051 on retro single board computers?

techknight · Joined: 21 Apr 2008 Posts: 231

So I have an old I/O card on a system that I am reverse engineering, and its an old 8051 style setup with external ROM, RAM, 8155 PIO chips, etc...

The CPU itself is a P8031AH.

Since I always used, and have a license for the AVR version of BASCOM, Does the 8051 version work with other chips than atmel's versions?

Would it work with the P8031AH?

Just curious before purchasing, Thanks

albertsm · Joined: 09 Apr 2004 Posts: 5921 Location: Holland

yes it works with other 8051 chips too.
you can best try with the demo first.

you can also consider using an AVR like 90s8515 or Mega162. the pinning is almost the same. the soft not of course.
8051 have limited ram. when you are used to bascom-avr, it is a step back.

but it will work. and you can try a lot with the demo.

techknight · Joined: 21 Apr 2008 Posts: 231

Thanks for the info!

But, the RAM on the 8051 board is actually external, there is a pair of Intel 8155 chips which have internal SRAM as well as PIO Ports.

But, I like the AT90S8515 idea. However, this board is part of a larger system that has a VME Bus with multiple cards. This is just one of the cards. This card only has LEDs, a 300 baud modem (wont use it), an AT Keyboard port hooked up to the 8031 serial UART, as well as an RS232 port that is using a separate UART IC, the Intel 8251.

Just to give you a little vision of what this board actually is.

Since I got the machine, I figured I could make it run again doing my own thing. It used to download its software over a satellite link which is long long gone. So its basically a braindead 68K machine which can be used for fun projects. Smile

My Initial thought was to just disassemble and reverse engineer the existing ROM code, but i am having a super difficult time following it, since it has jumps that go out into sections of ROM where there is no code at all, Maybe compiler obfuscated? I have already reversed the board back into a schematic and figured out its address map, so I know for a fact there are no peripherals at that address so I Dunno...

So my second thought is just re-writing it to just allow me to turn LEDs on and off, as well as using the RS232 port and the AT keyboard.