>From: "John Honniball" <coredump_at_gifford.co.uk>
>
>Jay West wrote:
>> Since the blank chips are nigh impossible to find anymore... is it possible
>> to use something like a PIC chip on a small DIP carrier card, that could be
>> plugged into an existing loader rom or microcode rom socket and function
>> just like the "real thing" to the system?
>
>You wouldn't use a PIC chip for something like this. A PIC would be
>used in a microcontroller-type application, where program-controlled
>behaviour is required. To replace a ROM, we could simply use another
>ROM (or PROM, EPROM, EEPROM, Flash ROM, etc.) with a pinout adaptor.
>
>People are already doing this for PROMs in mobile radios. These PROMs
>are in fact the same chips as one finds in a PDP-11 for booting (M9312)
>and for storing the 8008 firmware in an 11/34 console card. The
>PROMs in question are 82S131, 74S571 or Am27S13 types (512x8). I have
>some blanks here to fix a console card, as it happens.
>
>Scroll down here:
>
> http://www.open.org/~blenderm/syntorx/legacy.html
>
>to the section headed "EPROM Conversion" to read about the PROM
>replacements for Syntor radios. And see this page:
>
> http://www.open.org/~blenderm/syntorx/legacyeprom.html
>
>for photos of a completed adaptor.
>
>Do you know the chip numbers and/or specs for the ROMs you wish to
>emulate?
>
>--
>John Honniball
>coredump_at_gifford.co.uk
>
Hi John
Most of the applications Jay is talking about require faster
than 100ns someplace. Most EPROMs just are not in that range.
Dwight
Received on Thu Jul 29 2004 - 19:05:15 BST