{"id":39531,"date":"2026-04-03T20:00:00","date_gmt":"2026-04-03T18:00:00","guid":{"rendered":"https:\/\/www.jungsi.de\/?p=39531"},"modified":"2026-08-28T11:23:41","modified_gmt":"2026-08-28T09:23:41","slug":"q-save-sinclair-zx81","status":"publish","type":"post","link":"https:\/\/www.jungsi.de\/en\/q-save-sinclair-zx81\/","title":{"rendered":"Q Save [Sinclair ZX81]"},"content":{"rendered":"

QSAVE \u2013 Turbo Tape for the Sinclair ZX81 (PSS)<\/strong><\/p>\n\n\n\n

With the Sinclair ZX81, the cassette is simply part of the package. In practice, however, this also meant a lot of patience, a bit of luck with the signal level, and often several attempts before a program loaded properly. Especially with the 16K expansion, a save operation could feel like it went on forever. It was precisely during this period that QSAVE from PSS (Personal Software Services) appeared: a combination of software and additional hardware designed to significantly speed up saving and loading whilst making the process more reliable. I found a small advert for it in Happy Computer 11\/1983, and at the time it cost 79 DM.<\/p>\n\n\n\n

My copy in the collection<\/strong><\/p>\n\n\n\n

My collection includes a QSAVE in its original packaging, complete with instructions and the actual hardware \u2013 the \u2018Q SAVE Amplifier\/Filter Unit\u2019. Unfortunately, the software and cables are missing from my unit. This is not unusual for accessories from that era, as the small extras (cassettes, cables, adapters) tend to get separated over the years or eventually disappear \u2018into the cable box\u2019.<\/p>\n\n\n\n

The dating is intriguing: the packaging bears the \u00a9 1982 mark, whilst the instructions I have are dated \u00a9 1983. This fits well with a product that was launched in 1982 and later resold with revised printed materials.<\/p>\n\n\n\n\n\n\n\n

What QSAVE actually does<\/strong><\/p>\n\n\n\n

QSAVE is essentially a high-speed solution for the ZX81 cassette interface. Instead of using the relatively slow standard transfer rate, QSAVE employs a significantly higher data rate. This drastically reduces loading and saving times. At the same time, the aim is to reduce the susceptibility to errors \u2013 because whilst faster transmission makes the signal more sensitive, with the right processing it can ultimately run more stably than the \u2018original fiddling\u2019 with volume and the read head.<\/p>\n\n\n\n

It is important to note a typical side effect of such turbo systems: files saved in QSAVE format can generally only be reliably reloaded later if QSAVE (or a compatible tool) is available again.<\/p>\n\n\n

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\"Q
Q Save<\/figcaption><\/figure>\n<\/div>\n\n\n

Wie langsam war \u201elangsam” eigentlich?<\/strong><\/p>\n\n\n\n

To understand why QSAVE had a market at all, it\u2019s worth taking a quick look at the bare figures. The ZX81 transfers data via cassette at a speed of 300 bits per second \u2013 that may sound abstract, but it soon becomes very concrete:<\/p>\n\n\n\n

Programme size<\/th>Standard (300 bps)<\/th>QSAVE (3.000 Bit\/s)<\/th><\/tr><\/thead>
1 KB<\/td>~27 seconds<\/td>~3 Seconds<\/td><\/tr>
16 KB<\/td>~7 Minutes 17 Seconds<\/td>~44 Seconds<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n