The 3000 parts were bit slice processors. There were only a few instructions involved in there execution. Much of the action was on in the code as you'd think of a typical uP. In other words, there were not specific I/O instructions causing various actions. In may cases, just having the processors access some specif address cause a I/O related action to take place. Such actions would not show up in a dump of the ROMs code. The processor mostly provided timing and in some cases, the transfer of data. This was typical bit slice programming. In order to understand what was happening, you'd need to both look at the code and study the boards hardware along with it. It would be better to emulate the specified commands that were sent from the multibus ports. Dwight ________________________________ From: cctalk <cctalk-bounces at classiccmp.org> on behalf of F.Ulivi via cctalk <cctalk at classiccmp.org> Sent: Wednesday, November 13, 2019 12:45 AM To: cctalk at classiccmp.org <cctalk at classiccmp.org> Subject: WANTED: iSBC-202 microcode image Hi everyone, I'm planning to expand my MAME-based emulation of Intel MDS-II systems with the support for double-density floppy disks. In particular, I'm thinking of emulating the isbc202 floppy controller because its architecture looks very interesting. This board was based on Intel's own 3000-series bit-slices. A necessary step for this work is finding the image of the 4 microprogram PROMs on the controller board. Has anyone on this list ever dumped these memories, please? Can you share the binary images with me? Of course, I'm going to properly credit you in the emulator sources. AFAIK this would be the first emulation of a Intel 3000 system. A side question: do you happen to know if the Intel CROMIS assembler for 3000 series has ever been preserved somewhere on the Net? The manual says it was provided to user as a set of FORTRAN IV sources. Thanks in advance for your help. --F.Ulivi