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AlphaMicro Systems AM1000, AM1200, & maybe AM100L drive replacement

curbie

Experienced Member
Joined
Mar 23, 2019
Messages
161
I’ve been struggling trying to get the scsi2sd running in any capacity, since August of 2019, and thanks to some crucial help from Roger Lewis (a board member here), this go round took only two weeks and I finally have my AM1000 booting from the SCSI2SD, and/or using it as a sub-system. So I thought I’d post my notes in case someone else needed a drive replacement on their old AlphaMicro.

Before You Start​

For me, starting a project only to stop it, half way through, while waiting for parts to be ordered and shipped in, is about as frustrating as it comes. So here is as list of stuff the SCSI2SD will need the complete the setup. Some are necessary (points [1,2] below), some maybe not (points [3,4,5] below), you can determine how you want to play that.

Necessary Hardware​

1. To power the SCSI2SD & upgrade firmware, while operating setup software (scsi2sd-util).
Long 10FT USB to Micro USB Data Transfer & Micro USB Charging Cable.
One of the many “gotcha” that added to my two year journey groping in the dark. Some cables are just for charging!
https://www.amazon.com/gp/product/B07KC5169G/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

2. To perminately power SCSI2SD as a fully setup disk drive.
4 Pin LP4 5.25" Molex to 3.5" Floppy Drive 4 Pin Female FDD Power Adapter Cable 7.5-inch
https://www.amazon.com/gp/product/B0837D3Y5G/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

Optional Hardware​

3. To connect a SCSI2SD to the external I/F port on the back of an Alpha Micro.
SCSI 1 cable 50 Pin Centronics male/male 11" long 50 wires flat cable int/ext.
*** Note *** I cut this cable in half, and added male 50-pin ribbon cable connectors to the ends, for 2 cables.
https://www.ebay.com/itm/273672119488

4. To guarantee initial setup and operation.
Lerdisk 6-Pack 512MB Micro SD Card with SD Adapter
https://www.amazon.com/gp/product/B09JBD783H/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

5. To make disk copies.
UGREEN SD Card Reader 4 in 1 USB 3.0 SD TF CF MS Memory Card Adapter 5Gbps Read Write Simultaneously for SD SDXC SDHC CF CFI TF Micro SD Micro SDXC Micro SDHC MS MMC UHS-I Cards for Windows Mac Linux
I also create disk image files of the SD card to store and backup on my linux machine. I create and store disk image files of 512Mb. SD cards because my AM1000 recognizes all SD card I’ve tested (.5 ,1,2,4,16Gb) as 14 logicals with a bitmap of 4008 words ~64102 blocks. So, a stored 512Mb saves room on my linux machine (not a big deal), and restores to the larger than 512Mb SD cards I’ve tried.
https://www.amazon.com/gp/product/B01ARAH6O0/ref=ppx_yo_dt_b_asin_title_o05_s01?ie=UTF8&psc=1

Setup​

1st. Consideration is boot proms, old AM1000’s & some AM1200 didn’t come with proms to boot SCSI-1 drives, only ST506/MFM drives over the Alpha’s SASI/SCSI-1 drive interface, so no matter what old Alpha you’re trying to boot, to boot from a SCSI2SD, your old Alpha must have proms that will that will initialize & sense the SCSI-1 drive, then boot from it. (if you’re stuck on boot proms, PM me I might be able to help) Also some AM100/L’s may have an IACC SASI/SCSI-1 drive interface board, I know we sold a bunch and I wrote and still have boot prom code for it, and may take on a SCSI update if there is any interest.

I used a SCSI2SD V5.2 found here: https://store.inertialcomputing.com/product-p/scsi2sd-v5.2-2x-freeship.htm

I’m a linux guy, and tried to use linux and it was another one of the many “gotcha” that added to my two year journey groping in the dark. I don’t know yet what the issue was and I will re-visit this as time allows but I setup on a used/$100.00 HP laptop running windows 10 using setup software (scsi2sd-util) and firmware found here:
https://www.scsi2sd.com/v5/releases/v5.2.0/

These are the “General Setting” & “Device 1” tabs settings I used for the boot device in the scsi2sd-util setup software I used as on myAM1000. As a sub-system, the “General Setting” tab is the same but the “Device 1” & “Device 2” tabs settings are different. The “Enable SCSI Target” check-box is disabled on the “Device 1” tab graying everything out, and on the “Device 2” tab the “Enable SCSI Target” check-box is enabled. All the “Device 2” tab setting are the same as pictured for the “Device 1” tab except for the already mentioned “Enable SCSI Target” check-box is enabled, and the ‘ “SCSI ID” number is set to whatever “sub-system number” you choose while using “FIXLOG” to create your sub-system driver (1-3).

1643852626977.png 1643852687197.png

curbie
 
Last edited:
I saw this mistake yesterday and need to correct it, the information on the “Device 1” tab is for a two 2Gb SD card, which was part of a test I was running, this is the information the “Device 1” should have had. 2Gb SD would work, but is not my recommendation for the initial setup.

My apologies for any confusion.

Curbie



1644081118840.png
 
Well, I’ve now a bootable image for both 1.4A and 1.3D, I zipped each and the best I can get is a ~33Mb zipped image. I’m guessing my best bet would be to start web-site to store and distribute these images, boot prom images, terminal images.

Does anyone have a better idea?

Curbie
 
Well, I’ve now a bootable image for both 1.4A and 1.3D, I zipped each and the best I can get is a ~33Mb zipped image. I’m guessing my best bet would be to start web-site to store and distribute these images, boot prom images, terminal images.

Does anyone have a better idea?

Curbie
A lot of people just set up a shareable folder on something like dropbox... a lot easier than setting up an entire website.

I would be VERY interested in getting copies of your bootable images. I just aquired an AM1200, and it looks like it's not booting so I'm going to need an OS... let me know how I could make that happen.

I started working with Alpha Micros in the early 80s, with the S100 bus systems and we became dealer - I remember the excitement when we got our first CDC Hawk hard drive (5MB fixed, 5MB removable)!

I grabbed the AM1200 on a lark to play around (I've built retro/reproductions of PDP-8, PDP-11, Altair and Imsai too).
 
I started working with Alpha Micros in the early 80s, with the S100 bus systems and we became dealer - I remember the excitement when we got our first CDC Hawk hard drive (5MB fixed, 5MB removable)!
me too, graduated from Control Data Institute in 79, worked on CDC Hawk, Phoenix, & Trident drives, started working on AM100's, then alpha's full line as it came out.

I don't monkey with "free" services, but I'll email a bootable micro image or mail you a SD card if it comes to that, first i'll need to know what drive your 1200 is trying to boot from, to what terminal, on what port, at what baud rate?

Curbie
 
Control Data Institute - that's an old name. I attended the one in Minneapolis in 1975 as a Boy Scout "Explorer" when I was in high school! and then programmed the Cyber series in College at the University of MN.

I'd love an image sent...

Right now, as I just received the machine, I'm not certain of the drive type - Assuming the drive was original, the part number on the bottom is PRB-00060-00 - I'm trying to find what that translates to...

Port wise, Serial port 0, 9600,8,n,1 should be good.

My 1200 has the extended ports installed, which is cool... so I can run like 12 terminals. Back in the day I wrote and marketed a program called AUXSPL that was invoked during BOOT.INI and added the ability to the spooler to re-direct print jobs to the auxiliary RS-232 port on most dumb terminals. Paid for my graduate school fees.

I wish I had kept the code for it, best assembler I'd ever written.

I'll order the parts you mention above and we'll figure out the rest. I'll PM you my direct email.
 
Drive type is critical, if i recall correctly, the early 1200's booted from mfm drives though a 1410 xebec controller, more to the point, with mfm boot proms, while this scsi2sd card needs scsi boot proms to boot. the terminal/computer emulator you intend boot on is also important and should be in amosl.ini of the image.

curbie
 
I'll be using something like putty (VT100) to connect. I'm currently trying to get any output to the serial port from the self-test - during the '5b' portion of the test I should be able to tap the spacebar to get an autobaud setting and then start getting self-test messages, but so far, nada. :(

If I recall correctly, the AMs were particular about CTS/DTS or other control lines needing to be high for comms... Still trying to sort that out - might have to toss my logic analyser on the port..

FYI the SCSI2SD v5.2 cards are sold out in the source you mentioned. Is version 5.2 critical or any would any of their cards work do you think? I'm certainly willing to experiment.
 
another linux guy? you might want to check out my "Terminal emulator for Linux" thread here, procom on dosemu for a perfect wyse emulation.

my recollection of getting into self-test was holding down the reset with the power off, then powering on and releasing the reset.

my recollection of am-232 was it only cared about CTS on DB-25 PIN 4, although DCD is on pin 8 (I think Pin 18 on port 0 is remote reset)

i've used 5.1 & 5.2, not 6.0 but they are out of stock too, i would email them for an ETA. you still have to figure out that boot prom, or it doesn't matter what version of SCSI2SD you try, without the correct boot proms, the alpha won't sense the drive parameters, and no boot!

curbie
 
>>"my recollection of getting into self-test was holding down the reset with the power off, then powering on and releasing the reset."

That's correct. Works fine. I get the 5b - where it waits a bit to sense the terminal input (space bar) to figure out the baud rate. But it's not hearing anything form me, i suspect due to the pins not being held high. They're all 9-pin connectors on this machine (except for serial 3).

>>"you still have to figure out that boot prom, or it doesn't matter what version of SCSI2SD you try, without the correct boot proms, the alpha won't sense the drive parameters, and no boot!"

Right, I'm concerned that if I can't get a serial output in the self-test then moving beyond that may be pointless, so I'm focusing on what I can do right now to get to the next step. That feels like getting serial output to do something. :)

I have a friend who *may* have a disc stored away with matching boot proms. Won't know for a week on that one, but figuring I should move ahead on all fronts as there may be many different obstacles to get past.

Do you recall where the boot roms are located?

There seem to be a few scattered scattered about labeled 178-0x (x from 0 to 4), 178-00 and 178-01 also have (C) Alpha Microsystems, 1985 on them and rev B05. The rest are just 178-0x and A00, although I haven't removed the AM-706 memory card to see if any are hiding under there.

Step by step.

Can't thank you enough for your help... it's been 35 years since I've touched an AM-1x00. I remember popping them open all the time, but the memories are hazy...
 
There is about a million instructions to get to "5b", i can't image any serious problems other than not be able to find or acquire a ic or component.

the 1488 Tx drivers may be socketed on a 1200 like the 1000's, if so you can swap the 1488 for port 1 or 2 to port 0 to test that, i'm also wondering if you're getting any "garbage" to the screen? (incorrect baud rate) i think i recall a default baud rate of 300?

just checked the schematics for my 1000 and on a db-25, pin 5 also is RTS, my goof-up.

are you on linux, if so what version? for me at least, i had to give myself tty group privileges, and maybe others to communicate to a serial port.

i used a USB to Serial Adapter - 3 ft / 1m - with DB9 to DB25 Pin Adapter "out of the box" found here, and just tested it with GKterm from the linux software store,
then i setup procom, which gives perfect emulation. (vue, fix, stat, everything)

i think you found the boot proms, I may be able to help there too.

curbie
 
I read your terminal emulation thread, and I may go down that path... I did find (and you might be interested) that the emulator I use, ZOC Terminal, has Wyse 30, 50 and 60 capability among many others. I use it as it connects via SSH, Telnet, or serial... perfect for my growing legion of retro computers. Available in Windows and Mac versions.
But anyway, I wanted to share the news that there is another emulator out there to try. ZOC has a 30 day free trial, after which it becomes "nag-ware" depending on your needs. I'm using ZOC via serial to talk to my Altair 8800 reproduction via serial line so I'm fairly confident that part of the chain is working...

I'm using ZOC from my mac, but so far no output from the 1200 detected. I can configure the RTS and DTR pins high, but nothing. If I use actual RTS/CTS handshake I get a report saying that CTS is not detected. Interestingly, if I connect the cable to Serial 1 or 2 i get an apparent "loopback" with the characters echoing, which may indicate you are correct below.

I grabbed an RS232 breakout with LEDs from Amazon which may assist in debugging. And I may try to switch the Tx driver - they are socketed. Other than the "echo" on ports other than Serial 0, I'm not getting anything.

Thanks again!

the 1488 Tx drivers may be socketed on a 1200 like the 1000's, if so you can swap the 1488 for port 1 or 2 to port 0 to test that, i'm also wondering if you're getting any "garbage" to the screen? (incorrect baud rate) i think i recall a default baud rate of 300?

just checked the schematics for my 1000 and on a db-25, pin 5 also is RTS, my goof-up.

are you on linux, if so what version? for me at least, i had to give myself tty group privileges, and maybe others to communicate to a serial port.

i used a USB to Serial Adapter - 3 ft / 1m - with DB9 to DB25 Pin Adapter "out of the box" found here, and just tested it with GKterm from the linux software store,
then i setup procom, which gives perfect emulation. (vue, fix, stat, everything)

i think you found the boot proms, I may be able to help there too.

curbie
 
if ZOC isn't available for linux, i'm out of luck, but i'm real happy with procom.

since zoc emulates wyse 30, 50, 60 you are good to go with one of those.

Interestingly, if I connect the cable to Serial 1 or 2 i get an apparent "loopback" with the characters echoing, which may indicate you are correct below.
if i recall correctly, port 0 has it's own 1941 baud rate generator and clock crystal, where ports 1 & 2 share one, a bad port 0 baud rate generator or clock crystal "could" explain your symptoms? just a spit-ball.

AM serial stuff is pretty straight forward, data bus to 6850 UART, clocked by a 1941 baud generator and crystal, then through 1488 & 89's drivers and receivers, let me know if you need pin numbers to logic probe serial signals through there? I went though the same symptoms on my 1000.

curbie
 
sorry classic, i didn't understand your first offer, when i last FTP-ed, i needed a special FTP program, is that still the case?
 
if ZOC isn't available for linux, i'm out of luck, but i'm real happy with procom.

since zoc emulates wyse 30, 50, 60 you are good to go with one of those.


if i recall correctly, port 0 has it's own 1941 baud rate generator and clock crystal, where ports 1 & 2 share one, a bad port 0 baud rate generator or clock crystal "could" explain your symptoms? just a spit-ball.

AM serial stuff is pretty straight forward, data bus to 6850 UART, clocked by a 1941 baud generator and crystal, then through 1488 & 89's drivers and receivers, let me know if you need pin numbers to logic probe serial signals through there? I went though the same symptoms on my 1000.

curbie
I've got some RS232 troubleshooting tools now... Port 0 lights up the LEDs seemingly fine, but that's as far as I've gotten - been busy with other things this weekend.

I just built a circuit to decode an old VT100 keyboard and translate it to USB, which used an old 6402 UART - had to get experienced using my scope on that to debug my circuitry, hopefully that experience will pay off when i can sit down and start going through this. But something is happening at port 0... so that's kinda good news.
 
that is good news, i'll be around here if there is something else i might help you with, i'm redoing both os images for another member here so i hope to have my end buttoned down by the time you are ready.

curbie
 
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