Thanks so much for getting this working. Your MFM emulator is brilliant! On Tue, Nov 12, 2019 at 9:22 PM David Gesswein via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:

I got the Museum 3B1 operating again. The hard drive wasn't spinning up. I took the dead drive home and did a quick poke at it. Its not a stiction type problem, it just doesn't seem to be trying to spin up. The original drive was 40 MB. I put in a MFM hard drive emulator emulating the biggest drive the machine supports without modifications, 67 MB. I installed the OS, development tools, some games we had on our machine, utilities such as less, compress compatible with "current" compress etc, script to allow setting Y2k date, Kermit, and some demo programs which display slides with sales/promotional material. The basic I found was a DD copy which I haven't figured out the magic to write it to a floppy that can be used to install it. I ran out of time to install some of the things discussed such as Emacs.

The emulator does loose the distinctive sounds of the MFM drives. What do people think of emulated sounds? I've thought about adding it to the emulator but wasn't sure if it was just a gimmick.

I also replaced the soldered in coin cell battery with a battery holder and coin cell. The information I found online said it used a 2325. I put in a BR2330. The actual battery I found in the machine was a CR2430 which has slightly higher capacity. My understanding is BR batteries are a little less likely to leak so I like to use them though they have slightly less capacity.

I cleaned the dust out and it still worked. The foam that they put in instead of a left side fan is starting to deteriorate. It does not spring back if touched but isn't quite to turning to dust. I will replace it next time I open the case.

My original plan was to route an Ethernet cable from the emulator down into an unused expansion slot to allow easy access to update/backup the image on the emulator. I found the machine had all the slots full so couldn't do that. One has a memory board, the second a RS-232 & memory board, and the third the DOS-73 PC DOS board. For now the cable tucked behind the drive which requires the case to be opened to get to it. If we decide that we want better access there are a couple options.

1) Snake a cable out through the case such as the non used left side fan. Its convenient and won't be too visible but probably not the best option since I can be seen.

2) See if a smaller cable such as USB can still be snaked into the center expansion slot which has an easy to remove cover. The beaglebone in the emulator supports Ethernet over USB.

3) Wireless. The 3B1 has extensive shielding so probably would have to remote the antenna to outside the metal drive enclosure. This is probably overkill.

I gave a quick walk-through to Jeff on what can currently be demoed.

Future plans are to finish installing useful programs for demo on an emulator at home and update the image in the museum machine next time I visit. I'll also document what is installed and how to demo.

I also checked out the straight 8. The programs in memory were corrupted but it seemed to work fine when I reloaded them. I left it with the moving AC bits program and the punch letters on paper tape program loaded.

On Tue, Nov 12, 2019 at 9:22 PM David Gesswein via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote:

I got the Museum 3B1 operating again.. I put in a MFM hard drive emulator emulating the biggest drive the machine supports without modifications, 67 MB...

Hi, David, I'm happy to read about this. I have a 3B1 myself and the bearings on the hard drive are failing loudly. I happen to have a WD2010 controller chip for the easy upgrade, and I've thought about looking into the PAL/board mod to add an extra head. There's little point to the mods then trying to find a working MFM drive over 70MB but with an MFM drive emulator, size is arbitrary and might as well be large enough to do more than hold the full OS and a few local files. -ethan