Hi all,

I'm currently developing my own emulator and while testing Turbo BASIC's Readme.com, I ran into an issue: the program gets stuck in a loop, repeatedly trying (and failing) to allocate memory.

By reviewing the log of simulated interrupt calls, I found that Readme.com tries to allocate 0xFFFF paragraphs via DOS function 0x48. I’ve designed my emulator to prevent such large allocations since I assume a portion of that memory would already be reserved for BIOS and video memory.

Here's the relevant snippet extracted using the Netwide Disassembler (skipping the initial 732 bytes):

100000995  BBFFFF            mov bx,0xffff
200000998  B448              mov ah,0x48
30000099A  CD21              int 0x21

I'm curious—how does DOSBox (or even genuine MS-DOS) respond when a program tries to allocate such a large block of memory? Does it reject the request outright, return a specific error code, or perhaps fake a successful allocation?

Any insights would be appreciated!