pmandin/cleancode

Example source code for using the Atari hardware using all possible systems functions

cleancode's Issues

Bug in Mxalloc() detection

cleancode/common/mxalloc.c

Line 33 in 9dd4e6f

atari_mxalloc_avail = ((Sversion()&0xFF)>=0x01) | (Sversion()>=0x1900);

contains quite a suspicious code:

• it checks for major GEMDOS version 1.x (is there such?)
• it uses | instead of || for the check but it works by chance because previous condition always (?) fails

Getrez() + 2 is an unreliable way how to detect resolution

As discussed in our email conversation, there are at least two scenarios where I got vdi_vd.ttp crash in Falcon's 640x480@256c:

• if not using NVDI without AES (i.e. AUTO folder or FreeMiNT console), work_in[0] = Getrez() + 2 doesn't really work on Falcon. Getrez() produces a wrong number, leading VDI to believe that 640x480x8 is 640x400x1 in fact (in its work_out fields).
• if using NVDI without AES, you can't really write into the screen address. For some reason it seems the screen buffer is smaller than the actual resolution (perhaps related to off-screen bitmaps?). Try to boot into FreeMiNT console and run your vdi_vd.ttp - it will crash, badly (at least in 640x480x8)

In both cases, replacing work_in[0] = Getrez() + 2; with work_in[0] = 1; fixes the issue.