[vcf-midatlantic] 11/9 & 11/10 Workshop

[Dean Notarnicola]

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 at 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.
>
>