bit slice chips (was Re: Harris H800 Computer)

Paul Birkel pbirkel at
Sat Apr 23 01:32:36 CDT 2016

-----Original Message-----
From: cctalk [mailto:cctalk-bounces at] On Behalf Of Jecel
Assumpcao Jr.
Sent: Friday, April 22, 2016 10:54 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: bit slice chips (was Re: Harris H800 Computer)

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


Also the later Texas Instruments SN74AS888 (8-bit ALU slice w/ 16x8 register
file and multiply/divide/normalize) & SN74AS890 (sequencer).

Did these ever get any commercial traction?


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