29 Oct
2011
29 Oct
'11
11:51 p.m.
John Robertson wrote:
Has anyone tried to read the data from the Mostek 3851
PSU (ROM, I/O)
used with the 3850? I am looking to replace these tiny computers with a
modern FPGA or similar...
Dave McGuire wrote:
Holy cow, I think you've just found something
that a Data I/O
UniSite won't handle.
That's, umm, really unusual. (1702s
notwithstanding!)
Not particularly unusual. The MK3851 (and F3851) are not
field-programmable devices. There are a zillion non-field-programmable
devices that the Unisite can't read, as it was intended for
field-programmable devices.
I've read 3851 chips in the late 1980s, using an R6511Q 8-bit
microcontroller programmed to generate the appropriate bus signals. I
don't seem to have saved the code I wrote for it.
The more tricky problem was reading the code from an MK3870 single-chip
micro. When I did that, I didn't have a fast enough microcontroller, so
I used a board full of hardwired logic. Now there are plenty of
microcontrollers fast enough, and I have some more MK3870 series chips
that need to be read, so I need to design a new reader.