CST Expander?

[Wicksy]

Can I suggest that following some research on add-ons that the CST Expander didn't exist?

Computermate who sold the CST made Q Disc, mentioned at the bottom of their ads in QL User, that it would work with the Q+2 and Q+4 expansion boards (one month only the Q+2 is mentioned). No manufacturer was attributed to either card on the ads.

CST advertised the QPi centronics and Q+4 expansion card either side of this, and never promoted a Q+2 in any issue of QL User or QL World.

Soon after the Q Disc came out, Simplex were selling the Q+2 interface, you can see where I'm going with this?

Why CST weren't selling the Q Disc initially themselves I don't know, but later on they did as Computermate disappeared. Also, early in '85 Miracle were promoting their Double Expander, so with 2 similar cards on the market it wouldn't make sense for CST to compete. They had their own 4-port version to push.

I checked all CST ads from '84 to '86.

[Derek_Stewart]

Hi,

There is no doubt that the CST Q+4 expander existed, as a friend, had one attached to his QL. Alas, he is not with with us anymore and the I do not know what happened to the QL equipment.

[dilwyn]

A lot of companies made fairly simply passive two way expanders at the time, e.g. Adman Services.

They were often little more than two edge connectors soldered together, sometimes with minimal or no support for the expansion cards plugged in. Reminiscent sometimes of homebrew devices.

I had one of the Simplex Data Logic "Q+2" units for plugging in a disc interface and a RAM card without a through connector. It was cased in black plastic allowing the cards to slide in side by side. It stuck out both in front of and behind the QL, so you couldn't use the QL's plastic feet to angle the keyboard, for example. I don't remember if it had any electronics inside - passive two way expansion cage devices would not work on version AH or JM QLs if both add-on cards plugged in had onboard ROMs since the operating system gave up searching after finding the first (would work OK if the second device was a RAM card or similar without a device driver ROM). Explained in Pennell's QDOS Companion book. In fact, I had to quickly send the Q+2 back for a refund as it was too tight for the CST Q-Disk I had at the time, which caused the plastic case to split open. All told, I found the Q+2 disappointing.

SDL Q+2

SDL Q+2 inside view

Later, I got a CST Q+4. This could handle up to four plug-in cards, all of which could have onboard driver ROMs even on those early ROM versions - it had an onboard ROM which corrected the defect in pre-JS ROMs to allow them to find more than one such card. A short ribbon cable came from the base unit to its own circuit board which plugged into the QL expansion slot. The Q+4 was a big, heavy beast. Black metal-cased, it sat under the QL and needed its own power supply, which superficially looked like a QL power supply (it probably was a QL power supply, the connector looks similar in the picture below, I sold the Q+4 many years ago). No doubt CST produced it because they sold a range of expansion cards for QL - Floppy disc, Winchester drive, SCSI and Q-Pi parallel printer interface, RAM cards, RAM Plus, for example.

While the CST Q+4 certainly worked, it was a bulky device to add to your desktop - I only ever used it to combine a disk interface and a rare Maurice Computers QSV sound and voice synthesiser and occasionally a Q-Control Board (which was derived from a series in QL User or QL World magazine at the time, forgotten which of the two. When I lost interest in those cards, I sold them all, including the Q+4 as I didn't have room in the house I lived in at the time for all the computer gear I had in those days.

The Q+4's own interface card

Q+4

Q+4 PSU side view

Q+4 under a QL

cst_qplus4_and_wins.jpg (20.71 KiB) Viewed 552 times

EDIT: Removed incorrect reference to CST 2-way expander.

[RalfR]

I always found it interesting that certain connections in the BUS have to be buffered.

When I built my QL in a small PC case, I built a standing bus extension behind the mainboard, and also a slot for the QEP-III on the left side of the case, which you could plug in optionally. An Expanderam and a SuperQBoard were in the bus behind the mainboard and everything worked perfectly, without any buffering.

Perhaps it also depends on the QL itself whether this can work.

[Wicksy]

Re the last board: that's very interesting , but to my untrained eye am i seeing ram on the board and only one bus above it, as though it's an early version of the Ramplus?
It seems to have the positions for the 4 rom slots it would have on the board that goes in the QL.

I'll happily admit if am wrong.

[Wicksy]

I can see the word expander, possibly CST before it, 1985 and issue _ Dilwyn.

Edit. Just checked the QL Wiki for the Ramplus and it looks the same. It has expander written on the pcb.



Does anyone have a pic of the Miracle Systems double expander?

[dilwyn]

I assumed it was a 2 slot expander because its filename in my collection of photos was "cst_2slot_expander", wherever I got that name from at the time. Unless I just saw the word Expander on the PCB and assumed.

Yes, in the QL WIki picture by chr$ I can see the words "CST RAM+ Expander" on the PCB.

Ah well, another good idea bites the dust.

[Wicksy]

Yes, some of the Ramplus photos on the Wiki page are titled that and some as ram expander, possibly because of what is etched on the board.

That, and with the Computermate advert mentioning Q+2 and Q+4, someone has assumed they are both CST I think.
I didn't check any other magazines than QL User / World, as they had more QL news than others.

I agree on your observation on the Simplex b/plane, but I think the Expanderam with a disk interface in it looks equally ugly.

[dilwyn]

I've never seen a picture of the Miracle two card expander, the closest was the diagram they had in their early adverts (the one shown is from 1985), which hints at the same as the Wiki says, one slot facing leftward away from the QL and another facing backwards away from the circuit board - presumably there must have been a PCB bringing the edge connector out of the QL expansion slot.

The QL Wiki says it was quickly discontinued when through port connectors on RAM cards became a thing, so maybe only tiny numbers were ever made, if any?

[dilwyn]

That, and with the Computermate advert mentioning Q+2 and Q+4, someone has assumed they are both CST I think.

Sounds about right.