ttl DEFs from VDGint

**********************
* Defs from VDGint
* all offsets from 'U' (address of device memory area)
* (see p. 6-9, technical reference: U=start of driver data memory
*
* EDITION HISTORY:

*   Date    Changes Made
* -------- ------------------------------
* 91/05/07 Wrote original from VDGint source


* NOTE: There is LOTS of stuff which is only used once, and some which
* is not needed.  Here's a list of the un-needed, and un-used (other than
* once)
*
*  It would probably be benificial to patch VDGint to fix these problems,
* unless anyone else has ideas as to why VDGint is doing things this way.
*
* Un-needed
* VD.EPlt1  - (2) set to VD.NChar, and then read only
* VD.EPlt2  - (2) set to same as VD.EPlt1, and then unused
* VD.Chr1   - (1) set to same as VD.CChar, and then unused
* VD.PlFlg  - (1) initialized to $08, and unused
*
* Un-used
*
* $1D       - (1) end of SCF memory requirements
* VD.Strt1  - (2) CLRed, and then read (LDD) - left as $0000
* $24-$2B   - (8)
* $33-$34   - (2)
* $7E-$FF   - (130)
*
* total of 22 (150 in whole page) bytes unneeded or unused.

 page
VD.Start equ   $1E start of VD.XXXX data: number of VDG screens in use
VD.Strt1 equ   $1F (2) and another start
VD.Caps  equ   $21 caps lock info: $00=lower $FF=upper
VD.DFlag equ   $23 0=current screen is valid, $01-$FF = update video
* $24-$2B unused
VD.NGChr equ   $2C number of additional characters to get
VD.RTAdd equ   $2D (2) return address after getting characters
VD.EPlt1 equ   $2F (2) pointer to where to put next character
VD.EPlt2 equ   $31 (2) as above.
* $33-$34 unused
VD.CFlag equ   $35 true lowercase flag $10=true, $00=false
VD.CFlg1 equ   $36 VDG display code values
VD.DGBuf equ   $37 number of currently displayed buffer
VD.ScrnA equ   $38 (2) screen start address in system memory
VD.ScrnE equ   $3A (2) address of end of screen
VD.CrsrA equ   $3C (2) cursor address
VD.CrsAL equ   $3D cursor address low
VD.CChar equ   $3E value of character under cursor
VD.Mode  equ   $3F mode: 0=256x192 x2, 1=128x192 x4
VD.Chr1  equ   $40 same as under cursor character
VD.CColr equ   $41 cursor color
VD.Col   equ   $42 number of columns for this screen
VD.Row   equ   $43 number of rows
VD.TFlg1 equ   $44 see WRITE ($0E)
VD.Alpha equ   $45 0 when in alpha mode
VD.Rdy   equ   $46 device ready (see SS.DStat 0=not ready
VD.SBAdd equ   $47 (2) address of block screen is in
VD.Blk   equ   $49 Block number of screen
VD.GBuff equ   $4A allocation for graphics buffers (block#)
VD.AGBuf equ   $4B (2) additional graphics buffer
VD.HiRes equ   $4D hi-res screen table (block value
VD.NBlk  equ   $4E number of blocks in this screen
VD.SType equ   $4F screen type 0-4
VD.HR2   equ   $50 (3) for screen number 2
VD.HR3   equ   $53 (3) for screen 3 (same 3 bytes as above
VD.FF3   equ   $56 (2) data for flood fill
VD.FF4   equ   $58 (2)  "
VD.FF5   equ   $5A (2)  "
VD.FF6   equ   $5C  flood fill flag
VD.MTabl equ   $5D (2) address of mask table for pixels in byte
VD.PixBt equ   $5F bit mask for modes (0=$07, 1=$03 )#pixels/byte
VD.GCrsX equ   $60 graphics cursor X value
VD.GCrsY equ   $61 graphics cursor Y
VD.Msk1  equ   $62 mask byte 1
VD.Msk2  equ   $63 mask byte 2 (00,55,AA,FF)
VD.MCol  equ   $64 color? (C003,8001
VD.MCol2 equ   $65 color
VD.PMask equ   $66 pixel mask for colors (i.e. $55, $CC etc
VD.FF1   equ   $67 data for flood fill
VD.FF2   equ   $68 data for flood fill
VD.FFMsk equ   $69 flood fill mask
VD.FFFlg equ   $6A flood fill flag
VD.Palet equ   $6B (16) current palette values
VD.PlFlg equ   $7B initialized to $08 by L00DB, and then unused!
VD.NChar equ   $7C character to process
VD.NChr2 equ   $7D and the next one

* and RMB until we get 256 bytes reserved