These cards are no longer in production: Atomwide now produce the 'new' 1/2/3 port serial cards, at UKP 79, 89, and 99 pounds plus VAT respectively: mail sales@atomwide.co.uk for more information. The new design is fully compatible with all Acorn machines that have a standard size single-width podule slot, and uses a 4-layer PCB for full compliance with Acorn specs and performance.
The old cards can still run the latest software, but have some RiscPC compatibility issues:
Issue 1 cards used the NatSemi 16c552 dual 16550 chip. The maximum speed supported by this board was 115,200bps. Extremely early cards required a wire to be added to improve power distribution on the board - most shipped cards have this already. If your issue 1 card doesn't have it, here is a arc-ed drawfile which describes the fix.
Issue 2 cards used the Exar 16c552 dual 16550 chip. With this board, the maximum speed was upped to 230,400bps, which is supported by some ISDN TAs and Hayes modems. Unfortunately, the Exar chip is buggy in that the receive threshold FIFO setting appears not to work correctly: the driver software took this into account though, but in theory performance isn't quite as good as an issue 1 card, with a higher receive interrupt load.
Issue 3 cards, which are rather confusingly still labelled issue 2 on the PCB (the PCB fix for issue 3 was a single track being added - we didn't bother getting all the photoplots redone, just the ones for the layer in question). Issue 3 was a fix to make the card RiscPC compatible. However, as it was only tested in 2 and 4 slot RiscPCs, it only became aparrent later that it didn't work in 6 and 8 slot machines: the only cards that work in 6/8 slot machines are the Atomwide versions, being on 4 layer boards.
Issue 1 and 2 cards can be made to work in RiscPCs by removing the EPROM and by soft-loading the correct driver module on bootup (put it in the !Boot.Choices.Boot.PreDesk directory). An archive of the latest (v0.52) software for issue 1/2 cards without an EPROM is here.
The latest version of the software (v0.52) for cards with EPROMs fitted is here.
Any serial card with SerialDriver v0.51 or later can be used with the Serial port/Atomwide serial cards together with the Acorn/Aleph One PC cards. You require Release 1.91 or later of the PC support software, but apart from that there are no restrictions - the driver works with 386, 486 and 586 cards, and will work with either the podule or CPU slot versions. The serial card's extra ports are added to the PC environment from COM2 upwards, so if you have a dual port card you will get COM2 and COM3. The ports appear as 16550's and use the large RISC OS serial buffering, although due to flow control issues the send buffer is limited to 48 bytes.
The drivers have been tested with Windows 3.10, Windows 3.11/Workgroups, Windows 95 and DOS. Read the notes file before installing the driver as default IRQ settings have to be modified due to a conflict with the Acorn mouse emulation. The latest version of SerialCOM, v0.08, can be downloaded here.
This page is maintained by altman@cryton.demon.co.uk