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Agent Orange
June 1st, 2018, 05:06 PM
45903

NF6X
June 1st, 2018, 08:59 PM
That was a lot of computer for its time! Do you know when that ad was run?

smp
June 2nd, 2018, 04:23 AM
That was a lot of computer for its time! Do you know when that ad was run?

My best guess would be 1978. I had one of those in my store at the time. Mine was only a 64K with floppy disk version, but they claimed the capability to add a pile of memory and a Winchester hard disk. I never saw that in person.

smp

Agent Orange
June 2nd, 2018, 06:14 AM
That was a lot of computer for its time! Do you know when that ad was run?

No clue. I found it browsing on a site with no other info. It does mention "Looking ahead to the 80's", so like smp says, it probably from the late 70's.

Agent Orange
June 2nd, 2018, 10:11 AM
Nice little blurb on IMSAI . . .

https://www.imsai.net/history/ffc_hist/ffc_hist.htm

Tor
June 4th, 2018, 12:12 AM
My best guess would be 1978. I had one of those in my store at the time. Mine was only a 64K with floppy disk version, but they claimed the capability to add a pile of memory and a Winchester hard disk. I never saw that in person.

smp
The price isn't bad. I remember my school got a 10MB hard disk for their (core-based mini) computer, around 1979, after I had finished - I went and had a chat with the headmaster during Christmash holidays, and he told me they had finally managed to acquire one. But that HD cost them around $10k-$12k, depending on the exchange range, which I can't recall.

Chuck(G)
June 4th, 2018, 08:07 AM
Around 1978 you were not looking at 5.,25" winchester drives. I've got a Shugart SA4000 with controller from around then. It's a 14" drive and the controller is on a PCB the size of the drive--lots of TTL jelly-bean logic. The cost was completely justified.

Other options were included the Diablo 30 series disk drive--also very expensive and controllers weren't trivial.

NF6X
June 4th, 2018, 08:12 AM
The price isn't bad.

Agreed. I could see that system as a good investment for a small business at the time. If my memory is right, wasn't the IBM PC-XT the machine that really started making hard drives ubiquitous in small business computers, and began pushing down small hard drive prices with its sales volume? I thought that hard drives cost more around 1979, so I was surprised by the price tag on that IMSAI system.

Terry Kennedy
June 5th, 2018, 07:07 AM
Around 1978 you were not looking at 5.,25" winchester drives. I've got a Shugart SA4000 with controller from around then. It's a 14" drive and the controller is on a PCB the size of the drive--lots of TTL jelly-bean logic. The cost was completely justified.
Yup. 5.25" hard drives were a ways off at that point. You had a choice of minicomputer-type drives (often 19" rackmount types, usually without the rack). The earlier ones were 2315- or 5440-type drives, which had their own oddball interfaces (which often varied depending on who manufactured the drive assembly). Later on you had SMD / ESMD drives - I know of a number of systems that used the CDC Phoenix drive (possibly because Alpha Micro used them, so there was a built-in-reasonable-volume S-100 controller available). Later on you got drives which had more "smarts" in the drive and so a less-complex controller could be used. Corvus used some sort of parallel port, if I'm remembering right (the original black ones, not the later cream ones). Priam (later Vertex) also came out with drives that had the data separator, etc. in the drive. ADES (later renamed to ADSI because when their salespeople came calling and said "I'm so-and-so with ADES" it sounded like something else) had a nice S-100 controller for those. It was a lot faster than the Corvus-type drives. Eventually things coalesced around the ST-506 interface. ESDI was an also-ran, mostly because it never had the volume that ST-506 had, and once Western Digital got the idea to move a bunch of controller functions onto the drive we got IDE which meant that recording mode, bit rate, and (to some extent) geometry were things the host adapter didn't need to deal with. SASI had a number of issues - one of which was most drives were still ST-506 or ESDI and used a bridge board like a Xebec 1410, so the "standard command set" was anything but. Later on it got renamed to SCSI and sprouted a large number of incompatible cables and command sets. You had Apple SCSI, DEC SCSI, and so on. It didn't really get sorted out until LVD came around, and by that time the writing was on the wall and SCSI pretty much disappeared, to be replaced some time later with SAS (SCSI over a modified SATA transport layer).

NF6X
June 5th, 2018, 07:16 AM
What kind of hard drive was in that IMSAI computer system?

Gary C
July 4th, 2018, 09:52 PM
Yup. 5.25" hard drives were a ways off at that point. You had a choice of minicomputer-type drives (often 19" rackmount types, usually without the rack). The earlier ones were 2315- or 5440-type drives, which had their own oddball interfaces (which often varied depending on who manufactured the drive assembly). Later on you had SMD / ESMD drives - .

We had SMD's and 80MB CMD's at work. The voice coil and head assembly were so large, the floor shook when compiling a program. Still have a couple lying around but its a two person job to move them. The platters make great wall clocks.