Is it possible to use a 1MB card one the 48SX

[fs5qc]

Is it possible to use a 1MB card one the 48SX?

I can’t really confirm if is possible.

http://ramcomputernot.com/1mb_blank_ram_...eship.html

[BillBee]

There might be a guru here who knows better but from what I recall when checking out the SX the answer is no.

Both ports of the SX are like port 1 of the GX 128kb only. The GX port 2 is the one where the larger cards work (in segmented chunks of 128kb IIRC).

Now if the question is, can it be partitioned to be detected as 128kb so it would work? That I don't know.

-Bill

[gege]

SX is limited to 128KB card and can't use GX card.
But I remember when I have my SX during my students I have a 512KB TDS card on my SX but it use a special software to switch bank.

[fs5qc]

Do you remember if it was a gx card or a sx card ?

(02-02-2021 06:38 PM)gege Wrote:  SX is limited to 128KB card and can't use GX card.
But I remember when I have my SX during my students I have a 512KB TDS card on my SX but it use a special software to switch bank.

[Dave Britten]

(02-02-2021 06:40 PM)fs5qc Wrote:  Do you remember if it was a gx card or a sx card ?

(02-02-2021 06:38 PM)gege Wrote:  SX is limited to 128KB card and can't use GX card.
But I remember when I have my SX during my students I have a 512KB TDS card on my SX but it use a special software to switch bank.

There are definitely SX-specific cards greater than 128 KB, though these all require some kind of bank-switching mechanism, either via special software, or possibly a hardware switch. But if you have a large card that says it's for the GX, then it will either not work, or simply work like a 128 KB card with the extra space ignored.

[fs5qc]

Ok so good luck for me to find a 128k card

(02-02-2021 06:40 PM)fs5qc Wrote:  Do you remember if it was a gx card or a sx card ?

(02-02-2021 06:45 PM)Dave Britten Wrote:  

There are definitely SX-specific cards greater than 128 KB, though these all require some kind of bank-switching mechanism, either via special software, or possibly a hardware switch. But if you have a large card that says it's for the GX, then it will either not work, or simply work like a 128 KB card with the extra space ignored.

[gege]

Yes it's a SX card, GX not available when I am student.

[rprosperi]

TDS made 256K and 512K cards for the SX and they work reliably. I have heard rumors that they also made 1MB cards, but have never seen one or even evidence they existed (price sheet, EduCalc Catalog, etc.).

These cards use 2 or 4 128K banks, but unlike those in the the 48GX, a special library must be installed, which has commands to let you switch/select the banks; only one of these banks is available at a time and this bank is always 'seen' by the SX as either Port-1 or Port-2 (based on where it is physically installed). But note that you can change banks under program control so access to this extra memory can be easily automated.

The library for switching can be found here:

https://www.hpcalc.org/search.php?query=...ch+library

There is no documentation, but the commands are easy to figure out.

On eBay, these cards are often listed as "48GX only", but you can tell which TDS (Tripod Data Systems) cards are this SX-compatible type by looking at the copyright date, conveniently printed on the bottom front of the card. All the cards I have (and have seen) are "Copyright 1991", which is 2 years before the 48GX was even introduced. They are not labeled as 48SX only, as at the time, the 48SX was the only machine that existed that used these cards.

[fs5qc]

The only tds card I can find on eBay are got gx write on it

(02-03-2021 12:57 AM)rprosperi Wrote:  TDS made 256K and 512K cards for the SX and they work reliably. I have heard rumors that they also made 1MB cards, but have never seen one or even evidence they existed (price sheet, EduCalc Catalog, etc.).

These cards use 2 or 4 128K banks, but unlike those in the the 48GX, a special library must be installed, which has commands to let you switch/select the banks; only one of these banks is available at a time and this bank is always 'seen' by the SX as either Port-1 or Port-2 (based on where it is physically installed). But note that you can change banks under program control so access to this extra memory can be easily automated.

The library for switching can be found here:

https://www.hpcalc.org/search.php?query=...ch+library

There is no documentation, but the commands are easy to figure out.

On eBay, these cards are often listed as "48GX only", but you can tell which TDS (Tripod Data Systems) cards are this SX-compatible type by looking at the copyright date, conveniently printed on the bottom front of the card. All the cards I have (and have seen) are "Copyright 1991", which is 2 years before the 48GX was even introduced. They are not labeled as 48SX only, as at the time, the 48SX was the only machine that existed that used these cards.

[rprosperi]

(02-03-2021 01:01 AM)fs5qc Wrote:  The only tds card I can find on eBay are got gx write on it

Like any rare or unusual item you want to buy on eBay, you have to be patient and take time to watch for it; there will certainly be more listed in the future, I've seen one appear (or possibly be re-listed) roughly every other month for years. I recall this, because I usually email the sellers to tell them these cards are for SX, most just assume they are GX-only. I've purchased about 4-5 of these over the years, so they are out there.

[fs5qc]

No the one I find on eBay is write gx on case of the card

(02-03-2021 01:32 PM)rprosperi Wrote:  

(02-03-2021 01:01 AM)fs5qc Wrote:  The only tds card I can find on eBay are got gx write on it

Like any rare or unusual item you want to buy on eBay, you have to be patient and take time to watch for it; there will certainly be more listed in the future, I've seen one appear (or possibly be re-listed) roughly every other month for years. I recall this, because I usually email the sellers to tell them these cards are for SX, most just assume they are GX-only. I've purchased about 4-5 of these over the years, so they are out there.

[rprosperi]

(02-03-2021 01:36 PM)fs5qc Wrote:  No the one I find on eBay is write gx on case of the card

The 256K and 512K that do work on the SX are marked as "TDS" and "Copyright 1991". If not marked that way, they are very likely only for GX, even if not marked "48GX". There may be none on eBay now, but there will be in the future, just keep looking, it may take weeks or months to find one.

[Kiwi]

If you put a HP 1MB card in slot 1 or 2 of the HP 48SX, you only get garbage on the screen (random vertical black lines). The same will happen if you put this card in slot 1 of the HP 48GX.
So, it's better not to put these cards in the wrong slots. It's not good for the HP48 and not for the card (and the data on it).