So my 11/73 system, in a BA23, has recently developed a memory problem and won't boot. The ROM diags show...
Expected data = 052525
Bad data = 052524
Address = 02740032
Looks like one bad bit on a chip. I replaced the card with a spare card, but it's too small and now RSX can't boot, I want to run some memory diags on the failed card, hoping that they will be able to give me some more clues as to which chip has carked it.
My XXDP RX50 only had disk diags on it, so I needed to add QBUS memory diags, VSMAC0 and VMJAB0 (sometimes listed as CVMSAC0 and CVMJAB0).
I used SIMH and an RL02 XXDP disk image to create a new XXDP RX50 disk image, comtaining the memory diags and the oft used ZRCHB0, the MFM disk formatter. Next I needed to copy the RX50 image to a physical floppy.
I have a set of tools for this - the client/server disk copying tools I wrote to load VMS and RSX on systems without OSes. They should work fine on an RX50, since they are controlled by an RQDX3.
I had a look at them, and relaized that the VAX server tool, LOCALWRITE, had been upgraded a while back, and the PDP11 client tool, REMWRT, was no longer compatible with it. LOCALWRITE and REMOTEWRITE had been updated to allow entering what unit number to write to, and what file to download (per suggestions and help from Hans-Ulrich Hölscher), as well as some changes to the communiction protocol used between them. (When copying to a PDP11, the VAX LOCALWRITE server is used, since I haven't written LCLWRT yet, a PDP11 version of the server task).
So I prodced a new version of REMWRT with the needed changes. They aren't interesting enough to describe. Here's the new version of REMWRT.MAC
Please see earlier blog post for the instructions about how to assemble, link, load and use it.
So, I used LOCALWRITE and REMWRT to copy the XXDP RX50 image to a real RX50 on the system in question. Copy worked fine, disk boots OK. Next step - take out the spare memory card and reinsert the bad one, and boot XDP and run the diags. Here's hoping for some useful info....
