RE: Re: [ql-users] Making PCBs (was Q40/Q60/??? Ultra IO card)
Thanks for all the information that's been posted in response to mine and others' questions on this subject. I've certainly learned a lot that I never knew before. Even though soldering all those wires onto veroboard is so tedious, especially when trying to pick up where you left of if you can't complete the job in one session (I usually write a list of connections to tick off as I do them, but invariably get engrossed and do a whole bunch without ticking them off), it's probably the easiest way with just primitive gear - as long as they keep making ICs in DIL packages... I'm largely ignorant of the analogue side of circuit design - induction effects (which I hadn't even considered until I read it here), input output capacitance (info you see in the DC Characteristics tables of the datasheets). I'm surprised my spaghetti-heaps of wires and ICs work at all as I just connect up the logic and leave the rest to luck (I do remember to use decoupling capacitors though). I like Peter's idea of a tutorial on building Q40 add-ons. I'd like it to be in QL Today though :o) Ian. P.S. I've been getting more and more disappointed with Maplin, who have been steadily discontinuing their lines of older ICs. They now only supply microcontrollers, a very limited range of SRAM up to 128k x 8 and the range of crystals and crystal oscillators is seriously depleted. RS Components (www.rswww.com) still carries a broad range including many of the old 8 bit MPUs and peripheral chips, sourced from OKI. -Original Message- From: tony Sent: 11 January 2002 18:31 To: ql-users Cc: tony Subject: Re: [ql-users] Making PCBs (was Q40/Q60/??? Ultra IO card) On Fri, 11 Jan 2002 at 12:44:08, wrote: (ref: Hb5f11cf080d.1010753047.ln4p1327.ldn.swissbank.com@MHS) What equipment do you use to apply the etch-resist pattern to the boards, etch them, and then bond them together? Is it all very expensive for a hobbyist to produce one-off boards for experiments prototypes? (Probably nothing as complicated as a Q40 board.) In comparison to, say, the cost of digital photography with film scanner, A3 printer, software, consumables? (Probably another stupid question from an ignoramus) I didn't - this was done outside. One simply sends them plotter files etc and they do it all from that. My one offs are breadboards. The sH was a sight to behold, but worked incredibly well. I know Stuart Honeyball produced some commercial boards but printing direct onto special film. How? He didn't have a laser printer at the time and I did them for him (8-)# It apparently worked very well, but there is loss of quality. No chance of .5mm romdisq type pitches by this method. -- QBBS (QL fido BBS 2:257/67) +44(0)1442-828255 mailto:[EMAIL PROTECTED] http://www.firshman.demon.co.uk Voice: +44(0)1442-828254 Fax: +44(0)1442-828255 TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG Visit our website at http://www.ubswarburg.com This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as a solicitation or offer to buy or sell any securities or related financial instruments.
RE: Re: [ql-users] Making PCBs (was Q40/Q60/??? Ultra IO card)
What equipment do you use to apply the etch-resist pattern to the boards, etch them, and then bond them together? Is it all very expensive for a hobbyist to produce one-off boards for experiments prototypes? (Probably nothing as complicated as a Q40 board.) In comparison to, say, the cost of digital photography with film scanner, A3 printer, software, consumables? (Probably another stupid question from an ignoramus) Ian. -Original Message- From: tony Sent: 11 January 2002 12:23 To: ql-users Cc: tony Subject: Re: [ql-users] Q40/Q60/??? Ultra IO card -Original Message- From: Norman.Dunbar Sent: 11 January 2002 11:29 To: ql-users Cc: Norman.Dunbar Subject: RE: [ql-users] Q40/Q60/??? Ultra IO card Silly question from a hardware ignoramus : what is a 6 layer (or 4 layer) board ? I suspect it is to do with the track layour, but all the boards I ever used were 'double sided' = 2 layer ??? Yes. Nasta will give the definitive reply of course - on one screen please. Last time I said this to Nasta, he said he was working on an 1800 x something screen - (8-)# I did my first 4 layer with Mplane, mainly for an inner 'ground plane' and a power layer - ie only etch away around vias (layer connections) and holes. Often the ground plane is there simply to reduce noise, but it makes it easy to provide the necessary higher current capacity and avoid voltage drops etc. However I found I needed to use the +5V layer for some signal lines as there was simply no room on outer layers. If a lot of signal layers are internal it nicely hides the pcb design from hackers (8-)# It makes design debugging (at pcb design stage) far more difficult. Until we get _real_ 3D monitors, separation is by colour only - not easy. A hologram screen would be very nice. -- QBBS (QL fido BBS 2:257/67) +44(0)1442-828255 mailto:[EMAIL PROTECTED] http://www.firshman.demon.co.uk Voice: +44(0)1442-828254 Fax: +44(0)1442-828255 TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG Visit our website at http://www.ubswarburg.com This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as a solicitation or offer to buy or sell any securities or related financial instruments.
RE: Re: [ql-users] Making PCBs (was Q40/Q60/??? Ultra IO card)
On 1/11/02 at 12:44 PM [EMAIL PROTECTED] wrote: What equipment do you use to apply the etch-resist pattern to the boards, etch them, and then bond them together? Is it all very expensive for a hobbyist to produce one-off boards for experiments prototypes? The real problem is the thru-hole plating, the chemistry is 'interesting' not to mention expensive. Apart from that, single or two layer non-plated can be made quite cheaply and VERY precisely. I used to do that a lot - and would still be doing it if only I could find a source of highly concentrated hydrogen perxide and not immediately be branded suspicios with terrorist overtones. You can get blank boards that have the photo-resist pre-applied. Film can be produced using drafting transparency and a laser printer. For very fine geometry boards 600DPI is a must and you have to experiment because passing the papaer through the printer changes the dimensions. Fortunately, most PCB design programs have the capability to enter correction factors. I have done hundreds of boards this way, some with tracks and spacings down to 8/1000 - more than good enough for even the smallest SMD components. Laminating could be a problem, but it is not insurmountable, especially for small boards. It is DIRTY though :-( Nasta
