Got HPDrive up but not working, other HP1000 tinkering as well

HP 1000 SYSTEM RESTORATION

HPdrive disk emulation facility

I received my HP-IB disk controller card (12821A) and cable last night, which means that I can set up the PC running HPdrive and attempt to boot from a disk image. I didn't think I have the right boot rom to access HP-IB drives, but I gave it a shot anyway, hand entering the code from the boot loader manual.

First up, I ran the tape diagnostics and ran the diagnostic for the 12821A card. Everything passed with flying colors. I then cabled up and began setting up the PC that runs HPdrive. 

Booting from a disk image presumes that the configuration of my system matches the RTE that is generated on the image. Since I have things in different orders, for example the TBG card is in 11 rather than 10, and undoubtedly many more, I didn't expect it to boot all the way up to a prompt. 

The boot loader ran, transferred something and branched to it, but that was where the software sat looping. Pretty likely it is trying to find the disc drive where it expects it. I think that I have to take one of two strategies to complete a bootup of RTE IVB:

1. shuffle my cards around to match the order in a known disk image I will use
2. use the simh simulator to run a system generation, building RTE to match my config

This will take some investigation time, both in researching the images I can find online and in figuring out how to generate an RTE IVB system from a system with different slot assignments.

I have an image from a 7920H disc drive which I can use to boot. Its configuration is:

  I/O slot 10 = 12791A Firmware Expansion Module
  I/O slot 11 = 12539C Time Base Generator
  I/O slot 12 = 12821A HP-IB Disc Interface
  I/O slot 13 = 13181A/13183A 7970 Magnetic Tape Data Interface
  I/O slot 14 = 13181A/13183A 7970 Magnetic Tape Control Interface
  I/O slot 15 = 12966A Buffered Asynchronous Communications Interface
  I/O slot 16 = 12880A CRT or 12531A/B/C/D TTY Interface (system console)

Therefore, I would have to swap the FEM and TBG back to their normal positions and shuffle everything else around in the card cage. Instead, I will do the reconfiguration bootup, shuffling IO assignments to match my machine which is . 

  I/O slot 10 = 12539C Time Base Generator
  I/O slot 11 = 12791A Firmware Expansion Module
  I/O slot 12 = priority jumper card
  I/O slot 13 = priority jumper card

  I/O slot 14 = 12821A HP-IB Disc Interface

  I/O slot 15 = priority jumper card
  I/O slot 16 = 13181A/13183A 7970 Magnetic Tape Data Interface
  I/O slot 17 = 13181A/13183A 7970 Magnetic Tape Control Interface
  I/O slot 20 = priority jumper card
  I/O slot 21 = priority jumper card
  I/O slot 22 = 12966A Buffered Asynchronous Communications Interface

I thought it best to get some experience first using simh (HP 2100) to boot up and learn how the reconfiguration works. Unfortunately, I get an unimplemented instruction aimed at the serial card which is acting as the client. Not sure what is happening, but will persist a bit with this.

In parallel, I set up the HPdrive PC to host the RTE image I have and attempted the initial reconfiguration boot process. There are several possible boot locations, corresponding to heads 0, 1, 2, 3 or 4 on the virtual 7920H but none seemed to proceed.

Next test session, I will set the PC HPdrive software into a mode that reports activity. I want to see that the software actually sees the requests from the boot loader code and provides data back to it.

HP 1000 processor memory

As part of buttoning up to prepare for my HPdrive testing, I reinstalled the cover plate that fits over the memory cards. The machine then failed its powerup diagnostics, due to the crappy ribbon cables that link all the memory cards to the processor, similar to the cables causing trouble for my firmware enhancement board. 

I removed the plate and all is well. Will leave it off for now. 

7906 disk drive

I received my disk alignment cartridge, new sealed in bag, which I can use once I have the heads cleaned and reinstalled. I still don't have the PCBs needed to use the disk service unit (DSU) tool, so the actual process of alignment remains unclear.