[Ql-Users] the heat!
hi all little reminiscence last week while we had rather more seasonal temperatures (ie it was warm), one of the most annoying aspects of computing in the 80s rapidly re-asserted itself: 1) QL would last about 15 minutes and then crash badly. 2) quickly check all the chips were seated properly. 3) wait 20 minutes for it to cool down 4) quickly rush to do the next bit of coding before it got too hot again. 5) back to step 3 i think i need to get a little noisy desk fan pointing at the heat sinks to complete the full 80s feel. any one got any tales of annoying little things which in retrospect are quite charming? cheers fern ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] the heat!
Hi, another aspect of computing in the early eighties - not related to heat (even if it had some potential to heat up the atmosphere) - were the competing interests for the (sole) TV set in the house. Kids of today can't really understand that. Cheers, Tobias -Original-Nachricht- Von: fernando gonzalez ferng...@gmail.com An: ql-users@lists.q-v-d.com Betreff: [Ql-Users] the heat! Datum: Thu, 23 Aug 2012 15:56:11 +0200 hi all little reminiscence last week while we had rather more seasonal temperatures (ie it was warm), one of the most annoying aspects of computing in the 80s rapidly re-asserted itself: 1) QL would last about 15 minutes and then crash badly. 2) quickly check all the chips were seated properly. 3) wait 20 minutes for it to cool down 4) quickly rush to do the next bit of coding before it got too hot again. 5) back to step 3 i think i need to get a little noisy desk fan pointing at the heat sinks to complete the full 80s feel. any one got any tales of annoying little things which in retrospect are quite charming? cheers fern ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] the heat!
Hi Tobias, On 23/08/12 15:22, tobias.froesc...@t-online.de wrote: Hi, another aspect of computing in the early eighties - not related to heat (even if it had some potential to heat up the atmosphere) - were the competing interests for the (sole) TV set in the house. Kids of today can't really understand that. They will. Just as soon as their Raspberry Pi arrives and they want to plug it into the TV! ;-) Cheers, Norm. -- Norman Dunbar Dunbar IT Consultants Ltd Registered address: Thorpe House 61 Richardshaw Lane Pudsey West Yorkshire United Kingdom LS28 7EL Company Number: 05132767 ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] the heat!
Norman Dunbar wrote, on 23/Aug/12 15:37 | Aug23: Hi Tobias, On 23/08/12 15:22, tobias.froesc...@t-online.de wrote: Hi, another aspect of computing in the early eighties - not related to heat (even if it had some potential to heat up the atmosphere) - were the competing interests for the (sole) TV set in the house. Kids of today can't really understand that. They will. Just as soon as their Raspberry Pi arrives and they want to plug it into the TV! ;-) (8-)# I find mine *does* need an external power supply when running some keyboards. The Apple keyboard for instance wouldn't work at all when Pi was run off my monitor usb. I know they say 700ma, but it can be a *lot* less than that. I suspect a wireless keyboard (and mouse if really wanted) and the pi would quite happily run off a TV usb output. Tony -- t...@firshman.co.uk http://firshman.co.uk Voice: +44(0)1442-828254 Fax: +44(0)1442-828255 Skype: tonyfirshman TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] the heat!
any one got any tales of annoying little things which in retrospect are quite charming? cheers fern If you ever had a ZX80, that thing got even hotter than a QL. It was rumoured back then you could fry an egg on it, although I'm not sure anyone ever dared to try! Amazingly despite getting so hot it would usually keep working reasonably well. An annoying feature of my first QL was that microdrive cartridges which were recorded on MDV2_ would usually not work in MDV1_ (or vice versa). And if you plug a ZX Spectrum microdrive drive unit into the QL expansion port there were several problems: 1. It faced away from you with a standard microdrive ribbon cable. You had to fold and crease the short cable to make it face the right way. 2. Spectrum microdrives would not format cartridges on a QL, though you could usually read and write OK. I think there was a bit of a speed difference IIRC, that Sinclair made changes to make QL drives work at higher capacity. 3. I never got to try this, but apparently if you strung six of those to the QL expansion port, the whole microdrive system would fail if you accessed MDV8_ - this is a feature of QDOS which Simon Goodwin documented in his rom bugs articles. There we are Fern, some more nostalgia for you! Dilwyn Jones ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] the heat!
From: Dilwyn Jones 2. Spectrum microdrives would not format cartridges on a QL, though you could usually read and write OK. I think there was a bit of a speed difference IIRC, that Sinclair made changes to make QL drives work at higher capacity. I have discovered this, when I have built my first QL-T (sic!). I have used the potentiometer on the mdv's PCB and if it runs at a bit (!) higher speed , it has got more sectors after a FORMAT mdv1_. BTW: If you put a germanium diode in the MDV select pin, you can access both mdv1_ and mdv2_ with one drive Was very good in a small dektop case. Cheers...Ralf ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] the heat!
On 23/08/12 16:26, Tony Firshman wrote: I find mine *does* need an external power supply when running some keyboards. Yes, the two USB ports are poly-fused to 100mA each. Some keyboards and/or mice draw more so the fuses kick in and increase resistance (why am I telling you this?) reducing current. This causes the keyboards to act like a QL with a dicky membrane, and misses keys or start auto-repeating at a huge rate. I have a USB wireless keyboard and mouse for mine, a Perixx Periduo 707 Plus, and it too draws too much from the USB port. Plugged into the Benq monitor's powered hub, though, it works as good as it does on my work laptop - both show the same problems such as it hangs unless I leave it connected after power up, for about 30 seconds - or I can unplug and replug the wireless dongle to get it working fine again. The Apple keyboard for instance wouldn't work at all when Pi was run off my monitor usb. I know they say 700ma, but it can be a *lot* less than that. 700 mA is the minimum required for the Pi, but the USBs are limited to 100 mA each. I suspect a wireless keyboard (and mouse if really wanted) and the pi would quite happily run off a TV usb output. There's a web page at http://www.elinux.org/RPi_VerifiedPeripherals which has a list of what works and what doesn't. Of course, I didn't find it until after I'd bought by keyboard! HTH My USB powered hub, separate from the monitor, seems to feed power back down the interconnect cable to the Pi. The Pi's power LED comes on when the hub has power and the Pi doesn't. :-( It also refuses to boot with the hub attached. It also kills the network when I connect the hub after booting the Pi. Guess what, I bought that before finding the above page as well! Sigh! Cheers, Norm. -- Norman Dunbar Dunbar IT Consultants Ltd Registered address: Thorpe House 61 Richardshaw Lane Pudsey West Yorkshire United Kingdom LS28 7EL Company Number: 05132767 ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] the heat!
Norman Dunbar wrote, on 23/Aug/12 18:37 | Aug23: On 23/08/12 16:26, Tony Firshman wrote: I find mine *does* need an external power supply when running some keyboards. Yes, the two USB ports are poly-fused to 100mA each. Some keyboards and/or mice draw more so the fuses kick in and increase resistance (why am I telling you this?) reducing current. This causes the keyboards to act like a QL with a dicky membrane, and misses keys or start auto-repeating at a huge rate. Interesting. Yes I knew about the fuses, of course, but not the capacity. However my Apple keyboard is fine when Pi is run off a USB charger, but not off the monitor usb port. The issue must be the monitor power limit, not the polyfuse limit. Do these polyfuses degrade at all I wonder? Tony -- t...@firshman.co.uk http://firshman.co.uk Voice: +44(0)1442-828254 Fax: +44(0)1442-828255 Skype: tonyfirshman TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] the heat!
From: Tony Firshman Ralf Reköndt wrote, on 23/Aug/12 18:18 | Aug23: BTW: If you put a germanium diode in the MDV select pin, you can access both mdv1_ and mdv2_ with one drive Was very good in a small dektop case. Fun if you try to copy form mdv1_ to mdv2_ (8-)# Tony -- Hehe ;-) no, never have tried this. I former tried to work out a digital way with a few NAND chips for doing that and was very surprisesed, that a single germanium diode hat done the work (after finding out, that my way didn't work). As usual, Sinclair made it easy ;-) Cheers...Ralf ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] the heat!
Am 23.08.2012 um 18:58 schrieb Dilwyn Jones: any one got any tales of annoying little things which in retrospect are quite charming? cheers fern 1. It faced away from you with a standard microdrive ribbon cable. You had to fold and crease the short cable to make it face the right way. I used to have a leftover drive from my Spectrum and never used it on the QL because of that. I seem to recall my cables were too short to be twisted to have that d**n thing the proper way round. And, facing backwards, it looked embarrassingly amateurish. 2. Spectrum microdrives would not format cartridges on a QL, though you could usually read and write OK. I think there was a bit of a speed difference IIRC, that Sinclair made changes to make QL drives work at higher capacity. Don't remember that. I /think/ format worked with my drive. But, too long gone….. Tobias ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
