[sebhc] H17 ROMS

[Dwight K. Elvey]

>From: "Patrick Rigney" <patrick at vintagecomputermarketplace.com>
>
>> > The H17 ROM is a 2316 ROM; I haven't checked pin-outs
>> > carefully, but I _think_ it can be duplicated with a 2716. My 
>> > prom programmer (Data I/O System 19) doesn't want to read the 
>> > 2316, but it can burn a 2716. If nobody responds sooner, I'll 
>> > verify the compatability (or not) with the 2316 and try to 
>> > burn a copy from my memory dump (which is what's posted to 
>> > the archive).
>> > 
>> > Jack
>
>Jack, continuing our off-line discussion on this very topic, I've made some
>interesting discoveries.  Here's what I've found.
>
>The only schematic I had handy that used a 2516 was for the SWTP MP-09 6809
>CPU board from Mike Holley's site.  Interestingly, the text description of
>the circuit says at first that the EPROM sockets on the board are 2716
>compatible, but the parts listing for the board says those socket positions
>take 2516 compatible EPROMs.  The schematic clearly shows, however, a
>2716-compatible pinout.
>
>I then started looking at the 2532 and 2732.  Unless the schematics I'm
>looking at are wrong, the 2532 has a different pinout from the 2732--the
>functions of pins 18 and 21 (a chip enable and A11) are transposed. I used
>the charts below and the schematics for the AIM-65 and Commodore PET as a
>reference (2332 consumers).  Both circuits show 2332s (masked ROM), but I've
>used (recently, like this past weekend) a 2532 on an AIM-65 without any
>issues, so I know the 2532 is a good replacement for the 2332, but using a
>2732 takes rework.
>

---snip---

Hi
 I'm not sure but I think my H17 board actually has
a regular 2716 on it. As Patrick mentioned, there were
a lot of optional select levels for the various xx16
ROMs. In my pile of ROM reading stuff, I have a couple
of sockets wired such that I can avoid accidentally
getting the programming voltage to the chips and
inversions for the various selects. I do this with
simple jumpers since the programmer is not a real active
circuit. In a real circuit, one might need an inverter.
 It isn't going to hurt anything to try a straight 2716.
Dwight


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