Simius Posted October 1, 2015 Share Posted October 1, 2015 There is a new device called True Interlaced Mode Graphics. Allows to increase the vertical resolution twice. The device generate fully RS-170A standard sync pulses with interlace. It requires only minimal software support (to change the screen address according to the bit3 of PMCTL register in the VBLK interrupt routine)The device have form of small (51x18mm) PCB with precision DIP40 socket, inserted between MB and GTIA chip. PAL or NTSC version, available within about 1 month. The price is US$25+shipping.An example of the operation - 8x16 matrix fonts - on the attached photo. 7 Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted October 1, 2015 Share Posted October 1, 2015 Looks great. Please give more info. Quote Link to comment Share on other sites More sharing options...
Simius Posted October 1, 2015 Author Share Posted October 1, 2015 Attached screen is made with two character sets. One set contains the even lines, and the second - the odd lines of the characters. All required software is: LDA PMCTL ORA #$08 STA PMCTL LDX #CHAR1:H LDA PMCTL AND #$08 BNE * LDX #CHAR2:H * STX CHSET JMP EXITVBL 1 Quote Link to comment Share on other sites More sharing options...
Rybags Posted October 1, 2015 Share Posted October 1, 2015 PMCTL - guess this is some spare bits within GTIA's address space? So, does this device wait for persistent HBlank command near the end of screen then insert the extra HSync pulses where required? Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted October 2, 2015 Share Posted October 2, 2015 What IC chips are used in this device? What signals to / from the GTIA does it intercept? How was it developed? Will it co-exist with VBXE? Details, please (from a hardware hacker point of view) Thanx! Quote Link to comment Share on other sites More sharing options...
Simius Posted October 2, 2015 Author Share Posted October 2, 2015 (edited) PMCTL - guess this is some spare bits within GTIA's address space? So, does this device wait for persistent HBlank command near the end of screen then insert the extra HSync pulses where required? 1. Yes, there is an additional bit in the familiar PMCTL ($D01D) register. The register is R/W now. Bit3 is the interlace on/off ( W ) and the frame parity ( R ) register. 2. No, device generates all pulses anew. Sync pulses from GTIA are no longer used. Edited October 2, 2015 by Simius Quote Link to comment Share on other sites More sharing options...
Simius Posted October 2, 2015 Author Share Posted October 2, 2015 What IC chips are used in this device? What signals to / from the GTIA does it intercept? How was it developed? Will it co-exist with VBXE? Details, please (from a hardware hacker point of view) Thanx! Altera EPM3032ATC44 is used. AN0, AN1, AN2, and FO0 are intercepted. One morning I got up and I had an idea. Yes, it will work with VBXE. 672x400 resolution is possible. 4 Quote Link to comment Share on other sites More sharing options...
Rybags Posted October 2, 2015 Share Posted October 2, 2015 Nice idea... yes, VBXE in the non VGA mode as per most installs doesn't generate any Sync pulses of it's own, so making software controlled interlace or hardware override as we have here totally possible. I guess you still follow the normal GTIA protocol, so the bag of tricks which rely on Antic bugs will still work? Quote Link to comment Share on other sites More sharing options...
phaeron Posted October 2, 2015 Share Posted October 2, 2015 I thought true interlaced video required half scanlines...? When experimenting with the DMACTL-based trick I found that it worked on an LCD TV but an older CRT TV refused to interlace the fields. Quote Link to comment Share on other sites More sharing options...
Simius Posted October 2, 2015 Author Share Posted October 2, 2015 I guess you still follow the normal GTIA protocol, so the bag of tricks which rely on Antic bugs will still work? I hope so. I thought true interlaced video required half scanlines...? When experimenting with the DMACTL-based trick I found that it worked on an LCD TV but an older CRT TV refused to interlace the fields. Yes. But this half-scanlines are invisible, because are going in the vertical blanking time. This device will work on CRT TV, but some flickering will be seen. As on the standard TV picture. Quote Link to comment Share on other sites More sharing options...
Rybags Posted October 2, 2015 Share Posted October 2, 2015 It seems TVs both old and new can be flexible in what they'll accept. By default most of the old Atari gear doesn't even bother to generate the few scanlines around VSync anywhere near what the broadcast standard was, but practically all analog TVs and most modern digital receivers are happy with it, though some digital gear esp LCD TVs just assume you have an interlaced signal whether it is or not. Broadcast standard = insert extra Sync level or return to blanking level at half scanline intervals, done in such a way that half a scanline is inserted. Atari method = no half scanline insertions. Atari "software interlace" method = DMACTL tricks to approximate broadcast standard every 2nd field. Other fields left alone. Quote Link to comment Share on other sites More sharing options...
+Larry Posted October 2, 2015 Share Posted October 2, 2015 Presume that there is no clearance problem between the device+GTIA and the keyboard on 600/800XL's or XE's? -Larry Quote Link to comment Share on other sites More sharing options...
Simius Posted October 2, 2015 Author Share Posted October 2, 2015 The device is as high as a precision socket. Increases the height of set about 4.5mm. Quote Link to comment Share on other sites More sharing options...
danwinslow Posted October 2, 2015 Share Posted October 2, 2015 (edited) I will take at least one. Edited October 2, 2015 by danwinslow Quote Link to comment Share on other sites More sharing options...
guus.assmann Posted October 2, 2015 Share Posted October 2, 2015 Hello Simius, At least one for me, and maybe also a couple for Steve Carden. Nice idea.... Are you also still working on Rapidus? I find that much more intresting. BR/ Guus Assmann Quote Link to comment Share on other sites More sharing options...
+MacRorie Posted October 2, 2015 Share Posted October 2, 2015 I will take at least one. Thanks Quote Link to comment Share on other sites More sharing options...
danwinslow Posted October 2, 2015 Share Posted October 2, 2015 Are you also still working on Rapidus? I find that much more intresting. Me too. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted October 2, 2015 Share Posted October 2, 2015 Are you also still working on Rapidus? I find that much more intresting. Over at AtariArea, Drac030 says he's trying to find time to finish the Rapidus firmware. Quote Link to comment Share on other sites More sharing options...
Roydea6 Posted October 2, 2015 Share Posted October 2, 2015 Pre order for one item.. Maybe more after the trial use of the first. Quote Link to comment Share on other sites More sharing options...
+Stephen Posted October 2, 2015 Share Posted October 2, 2015 I'd be interested in at least one. Quote Link to comment Share on other sites More sharing options...
gozar Posted October 2, 2015 Share Posted October 2, 2015 I'm in for two. Quote Link to comment Share on other sites More sharing options...
Mathy Posted October 2, 2015 Share Posted October 2, 2015 Hello guys I'm interested, but need to know/learn more about the difference on screen between the output of the Atari with and without this device. Sincerely Mathy PS now for the stupid question: Can we still use a lightgun? Quote Link to comment Share on other sites More sharing options...
atarixle Posted October 3, 2015 Share Posted October 3, 2015 to me it sounds like the output is still the same, but you now can switch between non-interlaced and interlaced output. A register holds if the odd and the even frame is shown, and you can switch between two different char's or two different graphic screens. (this devices doesn't seem to use any kind of continuing double-sized graphics screen). Quote Link to comment Share on other sites More sharing options...
Rybags Posted October 3, 2015 Share Posted October 3, 2015 That 's pretty much it - it's up to the user to switch character sets or show the alternate bitmap screen. Or you can just run with interlace enabled but do nothing - the graphics on a CRT will have a slightly more filled in look. Quote Link to comment Share on other sites More sharing options...
atarixle Posted October 4, 2015 Share Posted October 4, 2015 this device sound very interesting to me too ... I really like the idea of having twice the resolution physically thru interlacing and like to order one Quote Link to comment Share on other sites More sharing options...
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