DayStar Turbo 601
The Turbo 601 is an PowerPC accelerator card for older Apple Macintosh computers (IIci, IIsi, IIvi, IIvx and Performa 600) that can provide a less-expensive alternative to buying a new Power Mac. It began shipping in January 1995 and was originally available in a 66MHz version for the IIci only. A 100MHz version for the IIci was released shortly after.
A few months later 100MHz and 66MHz versions became available for the IIsi, IIvi, IIvx and Performa 600.
Early in 1996, the Turbo 601 for the IIvi, IIvx, and Performa 600 was discontinued (both 100 and 66MHz versions). John Carson got this note from DayStar on the subject:
We have discontinued our Turbo 601 for the IIvx, IIvi, and Performa 600 because it does not support thousands of colours (you'd be limited to 256 colours); nor does it support stereo or microphone.
The 66 MHz versions for the IIci and IIsi are also out of production now (the last production run was in August, 1996).
Update (21 Jan)
All versions of the Turbo 601 have been discontinued. When Andy Baird sent eMail to DayStar to query why the price of the Turbo 601 has never reduced he got the following two replies:
Thanks for your comment re pricing. Let me make two comments in return: We agree totally that the upgrades are too expensive. However, I can only assure you that we have trimmed the price of upgrades extremely close to cost already. We are not getting any further breaks on the PowerPC 601 chip cost--it has been bottomed out for a while. Plus the 15ns SRAM we use is very expensive since it is a specialized use. Additionally, in order to get higher speeds without "pushing" the motherboard, we use an armload of high-speed (high speed = high price) components. And the board itself. an 8-layer, dual-sided, high-density, dual-populated surface-mount construction, did not reduce in cost either. This said, I now need to inform you that the product has just recently been discontinued, since the 601 processor chip is no longer available at all. We have no remaining stock left, nor do the mail order companies that were carrying it, nor does Ingram, our distributor that sells to all the "little guys". Sorry we cannot comply with your wishes re price, but I felt an explanation might better help your perception of the matter !
Sorry for the confusion over our pricing. 1st of all the 66MHz versions were dropped to $499 in June of last year and we discontinued them as a product line in October of last year. 2nd, the 100MHz version is now a discontinued product for the same reason the pricing never dropped - no one makes the 601 processor anymore-- not Motorola or IBM. That you are able to buy 604 upgrades cheaply reflects the fact that the manufacturers are ending the life cycle on those designs and are now working on a new design at the higher 225MHz+ speeds we will be moving to with our Genesis line. In fact, the only products we now manufacture are 2- and 4-processor Multi-proccessing machines and the 2-processor upgrade cards (604e 400+) for the 7500, 8500 and 9500 series.