• Please review our updated Terms and Rules here

IBM ESDI Hard Drive Replacement

Al Kossow said:
IBM sold ESDI and DBA disks in the PS/2
The 3.5" drives with a single large edge connector like in the 50z are not ESDI, they are DBA

Click to expand...

The true ESDI controllers (https://www.ardent-tool.com/storage/ESDI.html) and (5-1/4") drives are for the PS/2 Model 60 and 80 (towers). "DBA-ESDI" is mixing up some circuitry of the controller and (3-1/2") drives from the 60/80 design (same electronics are there, but as you have stated, the connection became largely proprietary). DBA-ESDI started with the same 8031 microcontroller as the IBM 60/80 ESDI, but later changed to the 80C196Kx; Here is a page I developed to show the response to INT 13h, Function 1Ch, Subfunction 0Bh, an 'ESDI' ROM BIOS call: https://ibmmuseum.com/Interrupts/INT13h/INT13h1C0B.htm
 
To come full-circle to the Model 50Z question, there are replacement "risers" to run IDE and CF drives; The Procom 'PIRA' (https://www.ardent-tool.com/8550/Procom_Pira.html) of antiquity, and modern retrofits:

zzxio.com

McIDE - ZZXIO

Parallel Advanced Technology Attachment Micro Channel Architecture Bus Interface Adapter
zzxio.com zzxio.com
zzxio.com

McIDE-CF - ZZXIO

Manual Adapter description file (ADF) - The @71f1.adf file is required to configure the McIDE-CF adapter. XTIDE serial drive utility (serdrive.exe) - To use the serial disk drive functionality of the McIDEiCF you need a to connect the PS/2 to a host computer via a serial port. A modern computer...
zzxio.com zzxio.com

The 20Mb (MFM) drive and riser of the 8550-021 (Model 50 "Type 1" to the "Type 2" Model 50Z) can be replaced the same way (the back bracket comes off to fit); The drive/riser were the same implementation as the MFM controller of the Model 60/80 (https://www.ardent-tool.com/storage/MFM.html) and (5-1/4") drives, splitting the same electronics (80C51 controller) between the riser and (3-1/2") drive like DBA-ESDI.

The Model 25/30/25 286/30 286 proprietary planar HDD connection also has a solid-state replacement as well (on this forum under the 'XTA' topic)...
 
Chuck(G) said:
I think "IPL" was S/360+ IBMish. Older systems, IIRC, just called it "Program Load" or something to that effect.
CDC used "deadstart"
Univac used "bootstrap", IIRC.
Burroughs was a bit peculiar; it had "Cold Start" and "Cool Start"

This is all from memory.
Click to expand...
IPL is standard term used in modern data centers today.

Seldom does someone in a data center say "BOOT".

Just like we dont have disk drives in a data center, they are DASD.

This is mainly due to most all large scale data centers are dominated by IBM.
 
The ESDI drives were also used in the IBM System/36 model 5363s and 5364s. I know there would be a lot of interest (must be 5 or 6 of us by now... Ha) in an emulated drive.
 
Chuck(G) said:
CDC referred to them
Click to expand...

Chuck(G) said:
CDC referred to them as RMS (rotating mass storage). I suppose you could take an SSD and put it on a merry-go-round...

But then, an SSD isn't a "disc", is it? :)
Click to expand...
news flash..... a merry-go-round isnt a computer either. Maybe add a few parts......

But what IBM thinks is what counts.....they dominate modern data centers and really always have.

But not all things IBM thinks come to be.....they were out smarted on reverse engineering IBM PC.

Russia has reversed their mainframes.

But when your budget is as big as many 'countries federal budgets' you can get by doing a lot of things.

Lots of judges, government purchasers, decision makers all have retirement funds invested in IBM and always have.
 
Chuck(G) said:
I believe that the 3330 disk drive clones were built in Bulgaria...


What reverse engineering? When I bought my PC, for $99 I got the purple binder full of BIOS code and schematics. IBM was playing poker with all cards up.
Click to expand...
There are lots of internet articles explaining how IBM BIOS was reverse engineered which broke back of IBM keeping others from building clones.
Once this reverse engineering was done and most importantly, upheld by courts, IBMs hold was over.
Hardware was nothing special and in fact not as good as some other home computers of the time but it had IBM name.

I can remember people glaring at time they had bought a IBM. Like that really meant something and it was special or better than all other machines.

Slowly they found out nothing special about IBM except they just charge you a lot.
 
"Reverse engineering" is very different from "clean room cloning". I believe that both Phoenix and ERSO did the latter. I knew a fellow who was in on the ERSO effort and he described it in detail. Really, the BIOS was copied, at least for all intents and purposes. The machinations done to get around legal technicalities was less engineering than lawyering. This is in stark contrast to the Apple Mac ROM situation, where Apple's idea was to sue everyone who even looked shady. Have the original Macintosh ROMs ever been cloned?
 
You must log in or register to reply here.
Back
Top