Toshiba 68301 design


68301 partal layout

Toshiba 68301 partial layout


We had designed several 68008 boards, one 68000 board, and two S68070 boards. The Toshiba 68301 promised much better levels of integration for the 68000 family.

First things first — do the chips physically exist? Can they be purchased in small quantities? We designed a board and started the layout, but the next couple of projects would have such short delivery times, that we bought in VME based boards.

We learned the hard way not design a board based on promises out of marketing departments filled with science-fiction, moonlighting journalists in Silicon Wonderland. In this case, “A chip or six in the hand are better than anything on a datasheet”

The design was similar to the Signetics/Philips S68070 board we designed in 1993 and described here.

The design would have been in the early 1990s. Unfortunately, the chip did not include Ethernet. There were similar parts from Motorola, but slightly different part numbers. It seemed as if Toshiba and Motorola were filling in gaps in the 683xx family. The 68360 was announced about the same time, but did have Ethernet and was the start of the QUICC family. Not long afterwards, the PowerPC would replace the 68000 core in the 860 PowerPC, which was similar to the 68360 part. We would work on the PowerPC 860T in 2000 and a 68030 board in 1994. The 68301 design would simply die of old age and the six 68301s would remain in captivity.

Six 68301s in captivity

Six Toshiba 68301 devices in captivity (and in small numbers). Also a lot smaller than the original 68000 in a 64-pin dual-in-line package (almost 85mm long).