On 7/10/2020 1:17 PM, Jeffrey Birt wrote: > > I have been working on a MOS 8701 clock chip replacement that is just > a bit bigger than the original so it will fit into a C128 with the RF > shield cover in place. > > The design is based on Frank IZ8DWF's design from one of his videos. > The PCB size is about 0.5"x0.9" with the holes on 0.4" centers. This > was needed to make room for the SSOP28 clock chip. > > The 0.4" spacing required making a fixture to custom bend some leads > into a 'Z' shape. And another fixture is used to align the leads for > soldering. To make it even more fun the resistors and caps are 0603 > size which is about as small as I care to do without a proper > microscope. I built the first board this morning and it works!! It > takes a fair amount of time to build one of them, and you need the > special fixtures for the leads, but it was an interesting challenge. > > This version of the PCB uses cut pads to configure NTSC or PAL. I have > a new design that should do this automagically. I should have some of > those PCBs in a few weeks for testing. > > _at_IZ8DWF – Frank when I am able to confirm that PAL works, I will send > you some completed units, gratis. > > Links to images > > https://1drv.ms/u/s!AtH4vpaZnzX7kvswntJpVdEm6W-OrQ?e=4wnmac > https://1drv.ms/u/s!AtH4vpaZnzX7kvsts_rsv_eTHoKL7w?e=TlqTnX > https://1drv.ms/u/s!AtH4vpaZnzX7kvsuRF1lVXL5UNJLgA?e=NjEhZa > > Jeff Birt (Hey Birt!) > I can't find a picture at present, but I buy surface mount IC headers from a source in Asia that has a DIP 16 footprint. If you are interested, I can get some more information. -- Jim Brain brain_at_jbrain.com www.jbrain.comReceived on 2020-07-10 23:00:03
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