Pioneers of computing

[Jon Elson]

On 03/12/2019 07:23 PM, Paul Koning via cctalk wrote:
>
>> On Mar 12, 2019, at 5:51 PM, Murray McCullough via cctalk <cctalk at classiccmp.org> wrote:
>>
>> ...
>> I’ve written in my book on the History of the Microcomputer a history of
>> the processing chip as the timeline follows an approximation of:
>>
>> Late *1950*s – patent on integrated circuit by Texas Instruments
>>
>> *1950*s to *1960*s – move from vacuum tubes to TTL technology
>>
>>       programs/functions in ROM
> You turned two steps into one: vacuum tubes to discrete transistors (1958 to mid 1960s) then transistors to TTL SSI ICs (1965-1975 or so), then CMOS and LSI.  With some detours -- some high end computers using ECL, for example.
Yes, the IBM 360 was produced using discrete transistors and 
diodes on little ceramic hybrid modules until 1969 or so, 
when they finally moved into ICs.  The IBM 360/85 (really a 
prototype of the 370/165) was built in their version of ECL, 
in 1968.

Also, before TTL, there was RTL and DTL, and also MECL.
> Also, when you said ROM you probably meant semiconductor ROM (mask ROM); earlier there was core ROM, invented (two variations, one in the USA and one in Holland, apparently independently) around 1957 and first appearing in a commercial computer in the 1958 Electrologica X1.
>
>
IBM 360 models 30, 50 and 65 used capacitive ROM (they 
called it read only Storage) for their control store 
(microcode), called CROS, or CCROS for a semi-differential 
version in the 50 and 65.  The 360/40 used transformers, so 
TROS for microcode.

Jon