IBM System/370 Model 148
The IBM System/370 Model 148 (and the Model 138[1]) were both announced June 30, 1976[2]
Manufacturer | International Business Machines Corporation (IBM) |
---|---|
Product family | System/370 |
Release date | June 30, 1976 |
Discontinued | November 1, 1983 |
Memory | One or two megabytes of high-density integrated monolithic processor storage |
Website | Official website IBM Archives |
Not only were they both more powerful and better in price/performance than their virtualized[3] counterparts, but actually much lower in price[4][5]
The 148 and 138,[6] both of which were withdrawn November 1, 1983, were marketed as followups for those wishing to upgrade, respectively, their 370/145 and 370/135 systems.
Expanded capabilities
The 148 had four times the reloadable control storage of the 145,[7] enabling or enhancing features such as:
- APL Assist[8]
- Extended control program support - going beyond the language-specific APL Assist, this had wider scope, reducing CPU cycles needed to run the operating system.[9]
A new model of the IBM 3203 printer family, the Model 4, was announced. Rated at 1200 Lines/Minutes, it was intended to provide already-available 1200 LPM printing, but in a more compact form.
Field upgrades
Sometimes known as in-the-field upgrades,[10] this is a capability that even recently was not universal.[11]
IBM could upgrade a 370/145 that had been field-upgraded to a 145-2, resulting in a 145-3. This was a major accomplishment, compared to what is known as a "forklift upgrade" - out with the old, in with the new, often consuming valuable time.[12] [13]
Marketing considerations
An industry research firm said "may be described as early 380s programmed to act like 370s"[4]
References
- "System/370 Model 138". IBM Archives. IBM.
- "System/370 Model 148". IBM Archives. IBM.
- 135-3, 145-3
- "IBM 370/138, 148 Really 'Early 380s'? Users May Have Jump on Upgrades". Computerworld. July 5, 1976. p. 2.
- $350,000 for a 138 having 500K of memory, vs. $721,500 for a 135-3 with 500K - less than half the price!
- described as "mediumpowered System/370 computers" "I.B.M. Cutting Prices 20% on 2 Computers". The New York Times. March 2, 1978.
- 128K vs. 32K
- a Microcode-based feature that allowe for faster execution than a software-only approach.
- up to 20% for OS/VS1, up to 55% for VM/CMS.
- "Is it possible to upgrade a bCX1-R to a bCX1-CR in the field? (upgrade router to controller / router)" - http://buildingskb.schneider-electric.com/view.php?AID=7836
- "I am in the early stages of designing the TMS320F28377S into a new product and I would like to build in the field upgrade capability..." - https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/477654?Firmware-upgrade-in-the-filed-TMS320F2837xS-Delfino-Microcontrollers
- https://www.computerworld.com/article/3058252/data-storage/how-to-overcome-the-infamous-forklift-upgrade-challenge.html
- https://www.pcmag.com/encyclopedia/term/68928/forklift-upgrade