bit slice chips (was Re: Harris H800 Computer)

ben bfranchuk at
Fri Apr 22 22:36:47 CDT 2016

On 4/22/2016 8:54 PM, Jecel Assumpcao Jr. wrote:
> Eric Smith mentioned:
>> [2901 A, B, and C, CMOS versions]
>> [2903 and 29203]
>> [Intel 3001 and 3002]
>> [MMI 5701/6701]
>> [Motorola MC10800]
> I'd add the Texas Instruments SN74S481, SN54LS481 and SN74LS481 TTL 4
> bit slices. The Schottky version had a 90ns clock cycle and the low
> power versions 120ns. These were 48 pins chips and didn't have an
> internal register bank like the 2901. The idea was that you implemented
> a memory to memory architecture like the TMS9900.
> The TI SBP0400A and SBP0401A were I2L 4 bit slices. The 400 had an
> internal pipeline register while the 401 was designed for external
> pipelining. ALU operations took 240ns at 200mW. It had an 8 register
> bank besides the working register.
> All I know about these is what I read in "The Bipolar Micromputer
> Components Data Book", December 1977 edition. I have no idea if these
> chips were actually shipped or if they were used in any product.
> -- Jecel

I think the problem was memory at the time. What was the use having
a FAST bitslice machine, but real memory at the time was SMALL and SLOw.
Then if you could get a nice machine, you could never get out of the
School or Lab home  with you.
The  Lilith computer comes to mind here.
PS:   A computer design A few generations
after Lilith. Here a FPGA risc cpu and fast static memory.

More information about the cctalk mailing list