68kMLA Classic Interface

This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.

Click here to select a new forum.
Looking for the datasheet for a IIci's ROM chips.
Posted by: geokov on 2023-12-28 20:58:51
Still working on schematics, I have searched online for the datasheets for the ROM chips to no avail.
Posted by: eharmon on 2023-12-28 21:40:53
If I remember correctly, these are 23C1010-equivalent mask roms.

The part numbers on the chips are the specific ROM software on the masks.

You should be able to replace them with 27C010 EPROMs or equivalents.
Posted by: geokov on 2023-12-28 21:47:24
If I remember correctly, these are 23C1010-equivalent mask roms.

The part numbers on the chips are the specific ROM software on the masks.

You should be able to replace them with 27C010 EPROMs or equivalents.
Hi, thank you for taking the time to reply. I am not actually trying to replace them, I am just looking for the datasheets or just the pin configuration for the ones in my IIci.
Posted by: dougg3 on 2023-12-28 22:36:43
There is an old datasheet for the Toshiba TC531001CP mask ROMs online: https://pdf1.alldatasheet.com/datasheet-pdf/view/115080/TOSHIBA/TC531001CP-15.html

In general ROM chips tend to follow standard JEDEC pinouts. It is possible to register on JEDEC’s site and download the standards, but they can be overwhelming to go through. So it’s usually easier to find a datasheet for the part (or a similar one).
Posted by: eharmon on 2023-12-28 22:41:30
For a quick reference these pinout diagrams and data sheets should be valid: https://eharmon.net/retro/eproms/#27c010

(The Vpp is no connect for mask ROMs, otherwise they're the same.)
Posted by: Bolle on 2023-12-29 00:06:02
or just the pin configuration for the ones in my IIci.
That's how they're wired on the IIci:

Bildschirmfoto 2023-12-29 um 09.04.17.png
Posted by: Phipli on 2023-12-29 01:51:41
Not the original question, but if someone finds this thread looking for specs, they seem to run at 200ns in the IIci, so 200ns or faster parts would work.
Posted by: geokov on 2023-12-29 06:45:43
There is an old datasheet for the Toshiba TC531001CP mask ROMs online: https://pdf1.alldatasheet.com/datasheet-pdf/view/115080/TOSHIBA/TC531001CP-15.html

In general ROM chips tend to follow standard JEDEC pinouts. It is possible to register on JEDEC’s site and download the standards, but they can be overwhelming to go through. So it’s usually easier to find a datasheet for the part (or a similar one).
Thank you dougg3 🙂
Posted by: geokov on 2023-12-29 06:46:15
For a quick reference these pinout diagrams and data sheets should be valid: https://eharmon.net/retro/eproms/#27c010

(The Vpp is no connect for mask ROMs, otherwise they're the same.)
Thank you eharmon for the link. 🙂
1