TRS80 Model 1 Level II ROMs

From: Pete Turnbull <pete_at_dunnington.u-net.com>
Date: Thu Jun 17 16:25:25 2004

On Jun 17, 19:25, Witchy wrote:

> I've borrowed a universal device reader/programmer (MQP Pinmaster 48)
and
> I'm trying to dump the ROMs from my dead TRS80. It claims to be able
to read
> anything because of its completely configurable design (with an
appropriate
> adapter for non-DIP style packaging) and I've already dumped some
EEPROMS.

Sounds a bit like the MicroPross at CompSci, where I used to work.
 Very cool machine.

> However, it doesn't like either of the TRS80 chips (NEC 4K marked as
2332
> and 2364) nor the ROMs on my Tangerine Microtan 65 TUGBOARD (4K roms
again I
> think).
>
> This thing knows about over 6500 different *ROMs so maybe there's an
> equivalent name I can feed it to see if I can read these ROMs?

2332 is a standard mask-programmed ROM; lots of companies made them.
 uPD2332 is the equivalent of Intel 2332, Motorola MCM68A332, Mostek
MK3200, Texas TMS4732, Signetics 2663, etc. However, one the options
is how the outputs are enabled, controlled by pins 20 and 21. Each can
separately be specified before manufacture as active high or active
low. Some vendors also allowed a choice on pin 20, either a chip
select or a power-down/output-enable (different timing, different
effect on power consumption).

Also, a 2364 is an 8K ROM, but I expect you worked that out.

Check what the TRS80 expects the active level to be on each of those
pins (I'd guess active low), and that the programmer is doing the same.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York
Received on Thu Jun 17 2004 - 16:25:25 BST

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