DOS ain't dead

New kernel compression methods - X compressor layers (Announce)

posted by ecm  , Düsseldorf, Germany, 16.04.2020, 22:22

The difference in timing between this

> method=x
> size=72192
> ini size=6832
> alloc=344512 bytes = 21532 paragraphs
> 12.561

and this

> method=X
> size=68608
> ini size=6576
> alloc=362992 bytes = 22687 paragraphs
> 24.478

is due to the fact that the RxDOS kernel (second result, 24s) is compressed into two layers by the X compressor, whereas the debugger (first result, 12s) is compressed into only one layer. Dual layer operation means that the first layer's output is used as the second layer's input. The X compressor is called with -9 which makes it try adding layers until there is no more benefit in compressed size from adding another layer.

This is from building lDebug 24768bf20fbc:

Creating ldebug.com
Compressing...
Input size: 78144 bytes
Number of layers: 1
Output size: 65352 bytes

This is the RxDOS kernel 31a3a83363f6:

Creating RxDOS.COM
Compressing...
Input size: 96848 bytes
Number of layers: 2
Output size: 61716 bytes

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l

Complete thread:

• New kernel compression methods - ecm, 13.04.2020, 00:05 (Announce)
  • New kernel compression methods - ecm, 13.04.2020, 00:17
  • New kernel compression methods - tkchia, 13.04.2020, 14:23
    • New kernel compression methods - ecm, 13.04.2020, 18:31
      • New kernel compression methods - ecm, 13.04.2020, 18:35
      • New kernel compression methods - tkchia, 14.04.2020, 14:46
        • New kernel compression methods - fdkernpl - ecm, 14.04.2020, 17:05
        • New kernel compression methods - exeExtraBytes jump - ecm, 14.04.2020, 17:06
      • New kernel compression methods - tom, 14.04.2020, 20:06
  • New kernel compression methods - Updated lDebug lzd results - ecm, 16.04.2020, 17:29
  • New kernel compression methods - Corrections - ecm, 16.04.2020, 22:06
    • New kernel compression methods - X compressor layers - ecm, 16.04.2020, 22:22
    • New kernel compression methods - Updated lzd, new lzo - ecm, 25.04.2020, 22:23
      • New kernel compression methods - Updated lzd, new lzo - tom, 26.04.2020, 13:46
        • New kernel compression methods - UPX, 512 runs clarification - ecm, 26.04.2020, 20:17