![\"IMG_0329\"](\"http:\/\/wordpress.hertell.nu\/wp-content\/uploads\/2018\/12\/IMG_0329.jpg\")
<\/a><\/p>\nLooking at schematics<\/p>\n
this is “optional” seems to be connected to the audio in. I might remove this in the future. but for this card. I will populate it:<\/p>\n And then at the PCMCIA port:<\/p>\n Lets take a look at the shcematic again:<\/p>\n oh part of the nonsupported flash option.\u00a0 so. THIS can sure be skipped.\u00a0 Will be removed in future.<\/p>\n now all “normal” A1200 stuff is done.\u00a0 Lets talk about “extras” and lets begin with the Composite\/S-Video:<\/p>\n First of all before talking about the AD724 I have populated above the IDE Connector.<\/p>\n you can see 3 0ohm resistors that selects either PAL or NTSC.\u00a0 this is configured for PAL. Well\u00a0 the AD724 is the chip doing the composite and Svideo. instead of the obselete CXA chip on the A1200.<\/p>\n Now you need to populate the trimmable CAP. (THIS you can skip if you are using NTSC mode on the 2 top 0ohm resistors)<\/p>\n Here it is installed. AND I also installed the 22uF electrolyte.. (that cap is needed even for NTSC but not the trimable one)<\/p>\n and the oscillator. you can either take one off the A1200 board or add a new surfacemounted version.\u00a0 I have one from an old A1200 board: make sure the oscillator does not short with the SMD pads opinted out here on picture.<\/p>\n Now add the 220uF (huge) caps and composite connector. and you are done.\u00a0 the trim cap needs to be adjusted. NOTE: for Composite C53 is required.\u00a0 for SVideo C51 and C52 is required<\/p>\n Now time for the NMI (IRQ7) Add 3 diodes and the switch header:<\/p>\n When you short NMI you trigger a IRQ7..\u00a0 if no software handling IRQ7 is installed. you will notice that the machine just will pause when the button is pressed.<\/p>\n And when we are at it: add a Reset header<\/p>\n Shorting this and the machine will simply just reset.<\/p>\n <\/p>\n Now we have the Floppy SEL pad:<\/p>\n Usually you do not do anything here. but if you do want to have the possability of swapping DF0 and DF1.\u00a0 like having a gotek externally but want it to be df0 and the internal drive will be a df1.\u00a0 you can cut the trace between the holes and make a switch that swaps the positions of the SEL signal. more or less like: DIY Boot Selector<\/a><\/p>\n <\/p>\n ok LED.\u00a0 “optional”<\/p>\n this is a special led. it is not really connected anywehere.\u00a0 you can see a header at the top. this is input and output.\u00a0 the right hole is the input to the led.\u00a0 technically you can put in a led here and solder a wire to the right pad and to anywhere you want to trigger the led.<\/p>\n Here I installed the led and PNP transistor.\u00a0 most people I guess want this to be connected to PCMCIA activity. and that is actually the left hole. so by bridging those holes. “OPT” gets to be PCMCIA activityled:<\/p>\n BUT first you will need to add 2 resistors close to the floppy powerconnector:<\/p>\n R637 should be a 10K and R638 should be a 4.7K:<\/p>\n Now it is done.\u00a0 if you populate the empty location with a PNP transistor. that signal will also be present at the hole for the led board that is not connected here. (like on all A1200 actually)<\/p>\n <\/p>\n Then we have the A500 keyboard connector:<\/p>\n but I MUST confess.\u00a0 I have never really tried this \ud83d\ude42<\/p>\n <\/p>\n we also have 2 mystery holes: This is “fire” button of port 0 and 1.\u00a0 I did put them here to be able to access those signals if you want to do a automatical kickstart switch or so based on those.<\/p>\n We also have FAN power:<\/p>\n Here I populated the 5V port with a PC style fan connector.\u00a0 5V to let the fan run more quiet. (some fans does not work at 5V)<\/p>\n and to end with we have the extra powerconnector:<\/p>\n This can be used to get power to something you need.\u00a0 OR ADD extra power to the PCB if you have a BPPC+BVision where it is recomended to add extra power close to the CPU connector. (also in the manual for the BPPC\/BVision)<\/p>\n <\/p>\n All done..\u00a0 put all electrolytes in place.\u00a0 ready for ultrasonic:<\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n
\nthe Bottom resistor R63 tells alice what mode to start in as default.\u00a0 the other 2 is for the composite chip and timing.
\nso you MIGHT want to put a jumper or so on R63 if you want to be able to switch between PAL and NTSC screenmode.
\n(this however does NOT affect the PAL or NTSC Osciallator you have installed, the 28MHz one)<\/p>\n<\/a><\/p>\n
\n(this can ALSO be skipped in NTSC config)<\/p>\n<\/a><\/p>\n<\/a><\/a><\/p>\n
\nhere there have been reports of issues.\u00a0 it seems that SOME trimcaps works better than others.\u00a0 will investigate in this.<\/p>\n
\nThis is a handy tool for coders as some assemblers (asmpro etc) can enable a IRQ7 function that makes it possible to break eternal loops etc.
\nalso software for “freezing”\u00a0 similiar to the Final Cartridge on the 64:<\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n
\n<\/a> <\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n