Re: Memories of Old IBM Equipment (Was: Jobs running without a programstack)

John McKee wrote:

Continues to amaze me: IBM1301 Disk drive, as used on IBM 1401, had a maximum
capacity of (gasp) 2,000,000 characters. The pack did not weight twenty
pounds, but was definitely heavy enough. A floppy disk holds almost as much
and has faster access time to boot.

I can't recall the disk model we had attached to our 1401. However, I recall when we had it upgraded from 2.5MB to 5MB. The CE essentially removed something like a stop-screw that allowed the disk arm to travel across the full surface. I learned a valuable lesson that day.

Maximum sore storage for a 1401 was 16K characters. Character had 6 bits
BA8421, with a checkbit and a wordmark bit.

We had 8K base memory plus a 4K expansion box. The expansion box was perhaps the size of a washing machine or dish washer. (Definite wire/donut memory.)

I still miss the wordmark bits. You could do some cool stuff by setting them on/off at different addresses. Kind of like inserting null-terminators at different positions in a string.

Machine language, then Autocoder, IOCS, DIOCS... I don't miss "compiling (assembling)" IOCS stuff much.

Tom Liotta