Marcel Kilgus wrote:
Alexander Klock wrote:
...
- Is there a way to get software from the net onto microdrive
cartridges, e.g. with a cable or something?
This is a bit of a chicken and egg problem, it is possible using a
serial lead, but the QL does not come with terminal software... though
a simple basic program without much of a protocol might be sufficient
for starters. On the other side you could use a PC with my QPC
emulator (http://www.kilgus.net/qpc/), the demo can read files and
write to the serial ports just fine.
I think the max serial speed with an unmodified QL is however 9600
bps.
Unmodified, 9600 is specified as the max speed, but personally, without
error correction, and hardware flow control, I wouldn't recommend it.
Especially as the serial input buffers can get out of sync with themselves
if too much data arrives, with the result that there then appears an 11
character delay - when a character arrives, you get the character that
arrived 11 before it, but until a character arrives, you won't get any
characters, even though there are 10 awaiting collection; the only cure we
found was a reset.
But a disc interface really might be a more of a hassle free solution.
Disc interface is the easiest, but if you can get a boot strap serial
link[1] going you can use a program (eg kermit, if you can get the PC
version...got both here...somewhere) to do the later transfers with error
correction. (Out of interest, whilst at Uni, a friend wrote a terminal
emulator that emulates a VT52[2] and a Tektronic 4010 storage tube.)
[1] QPC may help you out here: use it to send a file transfer utility (eg
kermit) to the QL; you could then use that with error correction to send
others. Your best bet is to transfer QL files zipped to the QL and use a QL
unzip utility as it'll include the QDOS header information, in particular,
the data space for executables. You may be able to run the file transfer
utility in QPC.
[2]It actually more emulates the terminal emulator that the MicroLabs of
UCLCC wrote and put in the BBC micros that were used as terminals to EUCLID.
...
- Is there a kind of SCART-cable available? (The TV output is so
terrible...)
The TV output never was particularly good, I'd always prefer a
monitor.
If you want the (relevant) scart pins, they're:
8 -) Function switching 15 - Red[3]
16 -) see below 13 - Red Ground[4]
11 - Green[3]
20 - Video in[5] 9 - Green Ground[4]
7 - Blue[3]
21 - Common Ground 5 - Blue Ground[4]
20 - Sync
I'm not sure about function switching: I made no connections and it worked
with my monitor, but my info says:
Pin: 8 16 Result
0 0 Normal 'off-air' signal[6]
1 0 Composite input
x 1 RGB input[7]
[3] Impedence 75 ohm, Video Level 0.7V +/-3dB, +ve DC component 0 to +2V
[4] The grounds are all connected together on the scart connector of my monitor.
[5] Impedence 75 ohm, Video Level 1Vp-p+/-3dB, +ve DC component 0 to +2V
[6] I suspect that these are used by TVs to auto select. ie if both pins 8
& 16 are logic 0[8], there is presumed to be no signal on the scart
connector. If either (or both) go to logic 1[8], a signal is present on the
scart connector and automatically switches input to the source, waking up a
TV from standby (in which case, when they both return to logic 0, the TV
reverts to standby mode). If you can manually switch the input on the TV,
then these pins shouldn't matter.
[7] The QL RGB outputs are at TTL levels: +5V. Trying to use RGB direct
could damage you QL, your monitor/TV, or both - the signal levels ideally
need to be dropped somehow.
[8] Pin 8: Logic 0: 0 to +2V, Logic 1: +9.5 to +12V
Pin 16: Logic 0: 0 to 0.4V, Logic 1: +1 to +3V
RGB gives best output, but using Composite would give better output than TV.
Easiest is to get a scart<->Video input/output converter as then all you
need do is build a QL Din to phono cable (you'll need to connect pin 2 to
gnd, and either pin 1 or 3 to the signal: one is monochrome, the other
should be colour - not sure which is which as I've see different
specifications with it both ways round).
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