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Added VT100 ROM disassembly

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This commit is contained in:
Jeff Parsons 2016-08-03 15:11:59 -07:00 • committed by Jeff Parsons
commit c206669589
5 changed files with 4977 additions and 2 deletions
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5
modules/pc8080/lib/chipset.js
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@ -172,6 +172,9 @@ ChipSet.SI1978 = {
* Hence the CPU component in the VT100's machine.xml is defined as:
*
* <cpu id="cpu8080" model="8080" cycles="2764798"/>
*
* Beyond that, we don't really care about that particular 8224. I only mention it because knowing the CPU frequency
* is helpful for simulating some of the other circuits below that we DO care about.
*/
ChipSet.VT100 = {
MODEL: 100.0,
@ -223,7 +226,7 @@ ChipSet.VT100 = {
* If we assume that the CPU cycle count increments once every 361.69ns, it will increment roughly 88 times every
* time LBA7 toggles. So we can divide the CPU cycle count by 88 and set LBA to the low bit of that truncated
* result. An even faster (but less accurate) solution would be to mask bit 6 of the CPU cycle count, which will
* doesn't change until the count has been incremented 64 times. See getVT100LBA() to see the chosen implementation.
* doesn't change until the count has been incremented 64 times. See getVT100LBA() for the chosen implementation.
*/
DC011: { // generates Line Buffer Addresses (LBAs) for the Video Processor
PORT: 0xC2, // write-only

2
modules/pc8080/lib/video.js
View file

@ -280,7 +280,7 @@ Video.VT100 = {
LINETERM: 0x7F,
LINEATTR: {
ADDRMASK: 0x0F,
ADDRBIAS: 0x10, // 1 == ADDRBIAS_LO, 0 = ADDRBIAS_HI
ADDRBIAS: 0x10, // 0x10 == ADDRBIAS_LO, 0x00 = ADDRBIAS_HI
FONTMASK: 0x60,
SCROLL: 0x80
},